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CERNJuly/August 2019 cerncourier.com COURIERReporting on international high-energy

WLCOMEE GELL-MANN’S CERN Courier – digital edition COLOURFUL LEGACY Welcome to the digital edition of the July/August 2019 issue of CERN Courier. n p When CERN was just five years old, and the Synchrotron was preparing for beams, Director-General Cornelis Bakker founded a new Λ Σ0 periodical to inform staff what was going on. It was eight-pages long with a Σ– Σ+ print run of 1000, but already a section called “Other people’s ” carried news from other labs and regions. Sixty years and almost 600 Couriers later, high-energy are plotting a new path into the unknown, with the – 0 + update of the European Strategy bringing into focus how much traditional K0 K+ Ξ Ξ K*0 K* thinking is shifting, with new ideas and strong opinions in abundance.

η0 –0 The first mention of in theCourier was in March 1964, a few π– π+ ρ– ρp ρ+ months after they were dreamt up almost simultaneously on either side of 0 0 0 ω0 ϕϕ0 the Atlantic by George Zweig and Murray Gell-Mann, who passed away in ηʹ π May, and whose wide-ranging legacy is explored in this issue. Back then, the – 0 idea of fractionally charged, sub-nucleonic entities seemed preposterous. K– K0 K* K* It’s a reminder of how difficult it is to know what will be the next big thing – 0 + ++ in the fundamental-exploration business. On other pages, LHCb unfolds Δ Δ Δ Δ a ground-breaking analysis of CP violation in three-body B+ decays, nonagenarian former CERN Director-General reflects on lessons from LEP, and Nick Mavromatos and Jim Pinfold report on the cut and thrust of a Royal Society meeting on topologically non-trivial solutions of . Σ*– Σ*0 Σ*+

To sign up to the new-issue alert, please visit: – 0 http://cerncourier.com/cws/sign-up. Ξ* Ξ*

To subscribe to the magazine, please visit: http://cerncourier.com/cws/how-to-subscribe. Ω–

EDITOR: MATTHEW CHALMERS, CERN   Lessons from LEP DIGITAL EDITION CREATED BY DESIGN STUDIO/IOP PUBLISHING, UK CERN Courier at 60 European Strategy updates

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European strategy CLIC project leader Steinar Stapnes Infrared discovery New nebula spotted A life in colour Murray Gell-Mann, discusses linear . 7 in Cassiopeia. 11 1929–2019. 25

HiVolta (DT1415ET) A1515 Family SYx527 board NeWs PeoPle 8 Ch Reversible 1 kV/1 mA 16/14 Channel 1-1.3kV (1 - 3 mA) ANALYSIS ENERGY FRONTIERS FIELD NOTES CAREERS OBITUARIES European strategy update Three-body B+ decays Topological avatars High-energy Olga Borisovna Igonkina • Nb3Sn cavities • Break- violate CP • • IPAC goes down networking 1973–2019 • Dieter Up to 8 Ch. 1 kV bias Groups through tech funded stars in ALICE • CMS under • FuSuMaTech The CERN Alumni Renker 1944–2019 • High performance constrains charm– • HEP in Latin America Network is proving • Anton Oed 1933– in Lebanon and Nepal hadronisation • LUCID • Heavy ions and hidden a valuable careers 2018 • Jacques Soffer • The kilogram redefined luminosities. 15 sectors • Mexico hosts resource. 47 1940–2019. 55 Indipendent Channels Floating up to 5 kV • White dwarfs merge. 7 LHCP • 3D printing. 19 PMT-based, SiPM, MicroMegas, Hybrid-PMTs, Wire chambers, Silicon Strip Detectors, Silicon Drift Detectors, Proportional Counters, Photodiodes, Germanium Detectors, FeAtures and many others... GELL-MANN TRIBUTES CERN COURIER AT 60 Gell-Mann’s multi- Strong interactions Memories from We’ve been here Our solutions... fits them all! dimensional genius The steps that led to a Caltech before… A stand-out among full understanding of the Gell-Mann’s complex What six decades of other Nobel laureates. 25 strong force. 28 character and his rivalry stories tell us about the with Feynman. 34 strategic choices facing www.caen.it the field today. 30 Small details… Great differences Low Voltage Power Sup ge & plies Volta Pro oPINIoN DePArtmeNts igh duc H ts VIEWPOINT INTERVIEW REVIEWS K*0 K*+ FROM THE EDITOR 5 A Tovey Reflections on Lessons from LEP Radio-euphoria NEWS DIGEST 13 – –0 + Granada Herwig Schopper on rebooted? ρ ρp ρ LETTERS TO 43 0 00 Eckhard Elsen on the what can be learned for • Radiation • Guido ω ϕϕ THE EDITOR symposium of the future colliders. 39 Altarelli’s legacy – APPOINTMENTS 48 European strategy for Signatures of the K* K*0 • & AWARDS physics. 37 artist. 45 On the cover: RECRUITMENT 49 multiplets arising from Gell-Mann’s . 28 BACKGROUND 58

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hen CERN was just five years old, and the was preparing for beams, Director- W G e n e r a l C or n e l i s B a k k e r fo u n d e d a n e w p e r i o d i c a l to inform staff of what was going on. The first issue ofCERN Courier (right) appeared in August 1959. It was eight-pages long with a print run of 1000, but already a section called “Other people’s atoms” carried news from other labs and Matthew reg ion s. Si x yea r s l ater, w he n CER N l au nc he d a we e k ly bu l- Chalmers le t i n for st a ff, t he Courier for m a l ly b e c a me a n i nter n at ion a l Editor p u bl i c a t i o n. To d a y t h e m a g a z i n e c a r r i e s a r o u n d 40 e d it or i a l p a g e s plu s 20 i n a d v e r t i s e m e nt s, it s 2 2,000 pr i nt c o pi e s a n d website reac hing a global readership of more t han 100,000. Several transformations have taken place in its 60-year h i s t or y, m o s t r e c e nt l y a pr i nt r e d e s i g n. Ve r y s o o n, t h e Courier Number one The cover image of the first issue ofC E R N C o u r i e r. will have a brand new website, too. It’s the beginning of a n e w o n l i n e p u bl i s h i n g m o d e l w h e r e b y s t or i e s w i l l a p p e a r o n the Courier w r o t e o f “o p e n r e v ol t” c o n c e r n i n g t h e i r n a m e s – cerncourier.com in a t imely ma nner, wh i le offer ing g reater which included George Zweig’s “aces” arranged into “deuces” variety and flexibility in the volume and types of content () and “treys” (bar yons). It’s a reminder of how dif- t hat we can publish. ficult it is to know what will be the next big thing in the No w i s a n o p p or t u n e m o m e nt for t h e h i g h- e n e r g y p h y s i c s fundamental-exploration business. c o m m u n it y t o h a v e a n e w c o m m u n i c a t i o n t o ol a t it s d i s p o s a l. Readers sometimes ask how articles get into the Courier. We The update of the European strategy (p7 and 37) is bringing e n c o u r a g e a n y o n e w h o h a s a t o pic t h e y’r e p a s s io n a t e a b o ut, into focus how much the traditional thinking in particle a n o pi n i o n t h e y w a nt t o s h a r e or a r e s u l t or a pr oj e c t t h a t t h e highest channel density to save valueable installation space p h y s ic s a n d c o s m ol o g y i s s h i f t i n g, w it h n e w id e a s a n d s t r o n g c o m mu n it y s h o u l d k n o w a b o ut t o g e t i n t o u c h w it h o ut h e s- o pi n io n s i n a b u n d a n c e. Fl i p pi n g t h r o u g h a l m o s t 600 i s s ue s itat ion. Those who do so almost always find t he e x perience best ripple and noise characteristics of Couriers p a s t, it i s s t r i k i n g b o t h h o w m u c h h a s c h a n g e d i n rewarding, and Courier feature authors often say that it has j u s t o v e r h a l f a c e nt u r y, y e t h o w s o m e t h i n g s r e m a i n f a m i l i a r. benefited their project or career in some way. This issue also Bask in hindsight comparing past and present on p30, and includes a revived letters-to-the-editor section (p43). No up to 30 kV, up to 100 W per channel be reassured that it was no easier in times gone by to get suggestion is too weak or self-interested, and no comment next-generation accelerators such as LEP off the ground (p39). too harsh for us to take on board. “Editors are – and should pure LV compatible, pure HV compatible and mixed setup crates available b e – r u g g e d p e o pl e…”, w r o t e i n a u g u r a l e d it or R o g e r A nt h oi n e Strong perspective in August 1959 in an address to readers. I would only add that high class & quality precision low and high voltage supplies The first mention of the word “quark” in theCourier appeared a d o s e o f fe a rle s s ne s s a l s o b e ne fit s t ho s e w ho w a nt t o bre a k in March 1964 – the year of their invention by Murray Gell- into communication. interchangeable controller boards for networking and software control Mann, who passed away in May and is the cover theme of  Further articles marking the Courier’s 60th anniversary, this issue (p25, 28 and 34). Back then, the idea of fractionally including special focus issues on detectors and vacuum tech- charged, sub-nucleonic entities seemed preposterous, and nology, can be found at cerncourier.com.

FLEXIBLE CHANNEL Reporting on international high-energy physics COMBINATIONS CERN Courier is d ist r ibuted Editor Laboratory INFN Antonella Varaschin SLAC National Accelerator Production editor advertising); e-mail BY MODULAR to governments, institutes Matthew Chalmers correspondents: Jefferson Laboratory Laboratory Melinda Baker Ruth Leopold [email protected] CHANNELS and laboratories affiliated Associate editor Argonne National Kandice Carter SNOLAB Technical illustrator with CERN, and to Mark Rayner Laboratory Tom L eCompte JINR Dubna B St a rc hen ko Samantha Kuula A l ison Tove y General distribution individual subscribers. Archive contributor Brookhaven National KEK National Laboratory TRIUMF Laboratory Advertising sales Courrier Adressage, It is published six times Peg g ie R i m mer Laboratory Ac h i m Fr a n z Hajime Hikino Marcello Pavan Tom Houlden CERN, 1211 Geneva 23, per year. The views Astrowatch contributor Lawrence Berkeley Recruitment sales Switzerland; e-mail expressed are not Merlin Kole D G Cassel Laboratory Spencer K lei n Produced for CERN by Chris Thomas courrier-adressage@ necessa r i ly t hose of t he E-mail DESY Laboratory Los Alamos National Lab IOP Publishing Ltd Advertisement .ch CERN management. [email protected] Till Mundzeck Rajan Gupta Temple Circus, Temple production Kat ie Gr a ha m OPC-UA, SNMP Centre NCSL Ken K i nger y Way, Bristol BS1 6HG, UK Marketing and Published by CER N, 1211 Advisory board Guido Piragino Nikhef Robert Fleischer Tel +4 4 (0)117 929 7481 circulation Geneva 23, Switzerland Peter Jen n i Kurt Novosibirsk Institute Angela Gage Tel +41 (0) 22 767 61 11 Christine Sutton Riesselmann S Eidelman Head of B2B and Laura Gillham Claude Amsler Forschungszentrum Orsay Laboratory journalism Jo A l len Printed by Wa r ners NEW EHS FLEX HV Boards High Class Low Voltage Boards Controller Boards with Linux inside Philippe Bloch Jülich Markus Buescher Anne-Marie Lutz B2B commercial Advertising (Midlands) plc, Bourne, High Voltage Supply highly up to 16 channel LV for on site integrated EPICS IOC, SNMP, Roger For t y GSI Darmstadt I Peter PSI Laboratory P-R Kettle operations manager Tel +44 (0)117 930 1026 Lincolnshire, UK customizable through plug- frontend hardware supply saves OPC-UA and Webservices, M i ke L a mont IHEP, Beijing Lijun Guo Saclay Laboratory Ed Jost (for UK/Europe display Matthew Mccullough IHEP, Serpukhov Elisabeth Locci Art director advertising) or +44 (0)117 © 2019 CER N gable channels (by factory) cable and installation space also „bare metal“ use Yu Ry abov UK STFC Ja ne Bi n k s Andrew Giaquinto 930 1164 (for recruitment ISSN 0304-288X

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EuropEan Str atEgy Granada symposium thinks big

The open symposium of the European R Strom in the next few years, the dipoles nec- Strategy for (ESPP), essary for a hadron might take which took place in Granada, , from 10 to 15 years of R&D before construction 13–16 M a y, r e v e a l e d a v i br a nt fie l d i n flu x could start. a s it g r a p pl e s w it h h o w t o a t t a c k t h e n e x t The symposium also saw much dis- big questions. Opening the event, chair cussion about colliders, which of the ESPP strategy secretariat, Halina offer an energy-frontier collider Abramowicz, remarked: “This is a very but for which it was widely acknowledged strange symposium. Normally we discuss the technology is not yet ready. Concerning results at conferences, but here we are more futuristic acceleration technologies discussing future results.” More than based on plasma wakefields, impressive 10 different future-collider modes were results at facilities such as BELLA at Berke- under discussion, and the 130 or so talks ley and AWAKE at CERN were on show. and discussion sessions showed that ele- mentary particle physics – in the wake of Thinking ahead the discovery of the Higgs but so From colliders to fixed-target to astro- far no evidence of beyond the p h y s i c s e x p e r i m e nt s, s a i d F r a n c e s c o For t i (SM) – is transitioning of INFN and the University of , detec- into a new and less well-mapped realm tors face a huge variety of operating con- of f undamental e x plorat ion. Long view could be heading to crisis or revolution,” ditions and employ technologies deeply Discussions during said Hernández. entwined with developments in industry. Plain weird a morning coffee The accelerator, detector and com- Another difficulty, he said, is how to han- Theorist Pilar Hernández of the Uni- break at the puting technology needed for future dle non-standard physics signals, such as versity of Valencia described the SM as ESPP update. fundamental exploration are varied l o n g-l i v e d p a r t i c l e s a n d m o n o p ol e s. L i k e plain “weird”. The model’s success in and challenging. Reviewing Higgs- accelerators, detectors require long time describing elementary particles and their factory programmes, Vladimir Shiltsev, scales – it was the very early 1990s when interactions is beyond doubt, but as an head of Fermilab’s Accelerator Physics t h e fi r s t c o n c e p t u a l d e s i g n r e p or t s for t he all-encompassing theory of nature it falls Center, weighed up the pros and cons LHC detectors were written. short. Why are the arranged of linear versus circular machines. In terms of data processing, the chal- into three neat families? Why do neutri- The former includes the International lenges ahead are immense, said Simone nos have an almost imperceptibly small Linear Collider (ILC) and the Compact Campana of CERN and the HEP software mass? Why does the discovered Higgs L i n e a r C ol l i d e r (C L IC); t h e l a t t e r a f ut u r e foundation. The high-luminosity LHC boson fit the simplest “toy model” of circular – collider at (H L-L HC) pr e s e nt s a p a r t ic u l a r c h a l l e n g e, itself? And what lies beneath the SM’s CERN (FCCee) and the Circular Electron b ut DU N E , FA I R, BE L L E II a n d o t h e r e x p e r- numerous free parameters? Similar Positron Collider in China (CEPC). Lin- iments will also create unprecedented puzzles persist about the universe at colliders, said Shiltsev, are based on data samples, plus there is the need to large: the mechanism of inflation; the mature designs and organisation, are g e n e r a t e e v e r-m or e M o nt e C a rl o s a m pl e s. m a t t e r–a nt i m a t t e r a s y m m e t r y; a n d t h e e x p a n d a bl e t o h i g h e r e n e r g ie s, a n d d r a w At the same time, noted Campana, the nature of dark energy and dark . a wall-plug power similar to that of the rate of advance in hardware performance While initial results from the LHC LHC. On the other hand, they face chal- has slowed in recent years, forcing the severely constrain the most natural lenges including their luminosity and community to towards graphics process- parameter spaces for new physics, said number of interaction points. Circular i n g u n it s, h i g h-p e r for m a n c e c o m p ut i n g Hernández, the 10–100 TeV region is an H i g g s f a c t or ie s o ffe r a h i g h e r lu m i n o s it y and commercial cloud services. Forti and i nt e r e s t i n g s c a l e t o e x pl or e. A t t h e s a m e and more interaction points than lin- Campana both argued for better career time, she argued, there is a shift to more ear options but require R&D into high- opportunities and greater recognition “bottom-up, rather than top-down”, efficiency RF sources and superconduct- for physicists who devote their time to approaches to beyond-SM (BSM) phys- Normally ing cavities, said Shiltsev. detector and comput ing effor ts. ic s. T h e n e w q u a r r ie s i n c lu d e s a x io n-l i k e we discuss For hadron colliders, the three cur- The symposium also showed that the and long-lived particles, and searches results at r e nt o p t i o n s – C E R N’s FC C-h h (100 TeV), strategic importance of communications, for hidden, dark and feebly-interacting C h i n a’s S p p C (75 TeV ) a n d a h i g h- e n e r g y education and outreach is becoming conferences, sectors – in addition to studying the LHC (27 TeV) – demand next-generation increasingly recognised. , which has deep connec- but here we superconducting dipole magnets. Akira Discussions in Granada revealed a tions to many puzzles in the SM, with are discussing Yamamoto of CERN/KEK said that while a community united in its desire for a post- s much greater precision. “Particle physics future results lepton collider could begin construction LHC collider, but not in its choice of

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NEWS ANALYSIS NEWS ANALYSIS

that collider’s form. Stimulating some New working group to address ILC concerns AccelerAtors heated exchanges, the ESPP saw propos- als for future machines pitted against On 17 May in Granada, following Hori/KEK R (MEXT) that called for further Niobium-tin cavities for smaller accelerators each other and against expectations from the open symposium of the discussions on these thorny Cornell University Cornell the HL-LHC in terms of their potential European Strategy for Particle issues. Comprising two A team at Cornell University in the US necessary transverse size of the cavity physics reach for key targets such as the Physics, the first meeting of members from Europe, two has demonstrated that high-frequency is halved. A smaller cavity with a higher Higgs boson. a new international working from North America and three superconducting radio-frequency (SRF) frequency also demands a smaller cryo- group on the International from Asia (including Japan), cavities made from niobium–tin alloy module; what was once 1 m in diameter, Big questions Linear Collider (ILC) took the group will investigate and can be operated more efficiently than the typical size of an accelerating SRF Gian Giudice, head of CERN’s Theory place. The ILC is the most update several points, including: conventional niobium designs, repre- cryomodule, can now be roughly half Department, said that the remain- technologically mature of cost sharing for construction senting a step towards smaller and more that size. ing BSM-physics space is “huge”, and all current future-collider and operation; organisation economical particle accelerators. The vast majority of SRF cavities cur- pointed to four big questions for colliders: options, and was at the and governance of the ILC; SRF cavities are the gold standard for rently in use operate at frequencies of to what extent can we tell whether the centre of discussions at the An illustration of the ILC in Japan . and the international sharing the acceleration of charged-particle 1.5 GHz and below – a region favoured Higgs is fundamental or composite? Are previous strategy update in of the remaining technical beams and are used, for example, in the because RF power losses in a supercon- there new interactions or new particles 2013. Although its technology group was set up by Japan’s preparations. The working LHC at CERN and the upcoming LCLS-II ductor rapidly decrease at lower frequency. around or above the electroweak scale? and costs have been revised KEK laboratory in response group will submit a report to free-electron-laser X-ray source at SLAC. But this results in large SRF accelerating What cases of thermal relic WIMPs are since then, there is still no to a recent statement on the KEK by the end of September Currently, the material of choice for the structures. Cornell graduate student Ryan still unprobed and can be fully covered firm decision on the project’s ILC from Japan’s Ministry of 2019 and the final report will be best accelerating cavities is niobium, Porter successfully made and tested a con-

by future collider searches? And to what location, governance or funding Education, Sports, Culture, used by MEXT for discussions which frequently has to be operated at a siderably smaller proof-of-principle Nb3Sn extent can current or future accelerators model. The new working Science and Technology with other governments. temperature of around 2 K and requires cavity at 2.6 GHz with promising results. probe feebly interacting sectors? costly cryogenic equipment to cool the Downsizing Earlier this year, a team at Cornell led “Niobium cannot operate efficiently at Though colliders dominated discus- cavity in a bath of superfluid liquid Cornell student by Matthias Liepe demonstrated that 2.6 GHz and 4.2 K,” Porter explains. “But

sions, the enormous progress in neu- of state and to establish whether there cas, brought into sharp focus the global helium. The technology is only heavily Ryan Porter with a small, high-frequency triniobium-tin the performance of this 2.6 GHz Nb3Sn

trino physics since the previous ESPP is a first-order phase transition at high nature of modern high-energy physics used at large-scale accelerators, and not standard 1.3 GHz (Nb3Sn) cavities can be operated very cavity was just as good as the 1.3 GHz per- was clear from numerous presenta- density? and the need for greater coordination at smaller institutions or in industry due cavity (left) and the efficiently at a temperature of 4.2 K. formance. Compared to a niobium cavity tions. The open-symposium audience O f a l l t h e s c i e nt i fic t h e m e s o f t h e w e ek, at all levels. to its complexity and costs. highly efficient and While seemingly only slightly warmer at the same temperature and frequency, was reminded that masses, as electroweak physics generated the live- The open symposium of the ESPP Researchers around the world are compact 2.6 GHz than the 2 K required by niobium cavities, it w as 50 t imes more efficient.” established by neutrino oscillations, are liest discussions, especially concerning update was a moment for physicists to striving to remove some of the barriers triniobium-tin this small rise in temperature omits the “T h i s i s r e a l l y t h e fi r s t s t e p t h a t s h ows the first particle-physics evidence for how well the Higgs boson’s couplings to take stock of the field’s status and future. prohibiting broader uptake of SRF tech- cavity. need for superfluid-helium refrigeration. that you can get good 4.2 K performance BSM phenomena. A vibrant programme fermions, gauge and to itself can The community rose to the occasion, nology. Two major obstacles still need to The size of the cavity is inversely at high frequency, and it is quite promis- is under way to fully measure the neu- be probed at current and future colliders. aware that the decisions ahead will be overcome to make this possible: the related to the frequency of the oscillating ing,” adds Liepe. “The dream is to have trino mixing and in particular Summary speaker Beate Heinemann of impact generations of physicists yet to temperature of operation, and the size radio-frequency electromagnetic field an SRF accelerator that can fit on top of the neutrino mass ordering and CP vio- DESY cautioned that such quantitative be born. A week of high-quality pres- of the cavity. within it: as the frequency doubles, the t he table.” lation phase, while other experiments e s t i m a t e s a r e e x t r e m e l y d i ffic u l t t o m a k e, entations and focused discussions proved ATTRACT are probing the neutrino’s absolute mass though a few things stand out. One is how far things have moved on since the InnovAtIon Winners The cer studies and to single- visi- scale and testing whether they are of a the impressive estimated performance previous strategy update concluded in kick-off meeting ble-light imagers for adaptive Dirac or Majorana nature. f rom t he HL-LHC i n t he ne x t 15 yea r s or 2013. Discussions illuminated both the Europe seed-funds for successful systems and low-light-level spectro- Around a fifth of the 160 input docu- so; another is that a long-term physics immensity of efforts to evaluate the 170 technologies ATTRACT projects scopic and imaging applications. Among ments to t he ESPP were l i n ked to flavour programme based on successive physics reach of the HL-LHC and future took place in May. other projects connected with Europe’s physics, which is crucial for new-physics machines in a 100 km-circumference colliders, and the major task faced by major research infrastructures, four searches because it is potentially sensitive t u n n e l o ffe r s t h e l a r g e s t o v e r a l l p h y sic the European Strategy Group (ESG) in An event held at CERN on 20–21 May projects at the ESRF concern adaptive to effe c t s at sc a les a s h ig h a s 10 5 TeV, said reach on the Higgs boson and other key plotting a path to the future. It is clear revealed 170 projects that have been algebraic speckle tomography for clin- Antonio Zoccoli of INFN. Summarising parameters. There is broad agreement, that new thinking, from basic theory to granted €100,000 of European Union (EU) ical studies of osteoarticular diseases, a dark-matter and dark-sector physics, Shoji however, that the next major collider instrumentation, , analysis funding to develop disruptive detection novel readout concept for 2D pixelated Asai of the University of Tokyo said that a immediately after the LHC should collide and global organisation, is required to and imaging technologies. The success- detectors, the transferral of indium-gal- shift was taking place from the old view, and to fully explore sustain progress in the field. ful projects, drawn from more than 1200 lium-nitride epilayers onto substrates for where dark-matter solutions arose as a the Higgs and make precision measure- No decisions were taken in Granada, pr o p o s a l s f r o m r e s e a r c h e r s i n s c i e nt i fic f u l l-s p e c t r u m L E D s, a n d a r t i fic i a l i nt el- byproduct of beyond-SM approaches such ments of other electroweak parameters. stresses Abramowicz. “During the open and industrial organisations across the 19 of the projects, in areas from mag- ligence for the automatic segmentation as supersymmetry, to a new paradigm symposium we mainly discussed the world, now have one year to prove the nets and cryogenics to electronics and of volumetric microtomography images. where dark matter needs an explanation of The big picture science. Now comes the time to assess s c ie nt i fic m e r it a n d i n n o v a t io n p o t e nt i al informatics. Several of the selected “170 breakthrough ideas were selected its own. Asai called for more coordination The closer involvement of particle physics the capacity of the community to real- of their ideas. projects involve the design of sensors based on a combination of scientific and support between accelerator-based with astroparticle physics, in particu- ise the proposed scientific goals,” she The 170 funded projects are part of the or signal-transmission systems that merit, innovation readiness and potential direct detection and indirect detection lar following the discovery of gravita- says. “The Physics Preparatory Group is Horizon 2020 ATTRACT project funded by operate at very low temperatures or in societal impact,” explained Sergio Ber- dark-sector searches, as exemplified tional waves, was a running theme. It preparing t he briefing book, which will the EU and a consortium of nine partners, the presence of radiation, and many tolucci, chair of ATTRACT’s independent by the new European Center for Astro- was argued that, in terms of technology, The closer summarise t he scient ific aspirat ions of including CERN, the European Southern target applications in medical imag- Ideas were research, development and innovation Particle Theory. next-generation gravitational-wave involvement the community, including the physics Observatory (ESO), European Synchro- ing and treatment or in the aerospace selected based committee. “The idea is to speed up the Jorgen D’Hondt of Vrije Universiteit detectors such as the Einstein Telescope of particle case for them.” tron Radiation Facility (ESRF), European sector. Others seek industrial applica- on scientific process of developing breakthrough Brussel listed the many dedicated exper- are essentially “accelerators without physics with The briefing book is expected to be XFEL and Institut Laue-Langevin. The tions, such as 3D printing of systems merit, technologies and applying them to iments in the strong-physics arena and beams” and that CERN’s expertise in astroparticle completed in September. The ESG draft- successful projects are grouped into equipped with sensors, the inspection innovation address society’s key challenges.” the open questions, including: how to vacuum and cryogenics would help to ing session will take place on 20–24 four broad categories: data acquisition of operating cryostats or applications in The outcomes of the ATTRACT physics was readiness reach an adequate precision of perturba- make such facilities a reality. Inputs from January 2020 in Bad Honnef, Germany, systems and computing; front-end and environmental monitoring. seed-funding will be presented in tive and non-perturbative QCD predic- the astroparticle– and nuclear-physics a running and the update of the ESPP is due to be back-end electronics; sensors; and soft- ESO’s astronomical technology and and potential Brussels in autumn 2020, and the tions at the highest energies? And how to communities, in addition to dedicated theme of the completed and approved by CERN Council ware and integration. expertise will be applied to an imaging societal most promising projects will receive probe the quark– plasma equation perspectives from Asia and the Ameri- symposium in May 2020. CERN researchers are involved in spectrograph suitable for clinical can- impact further funding.

8 CERN COURIER JULY/AUGUST 2019 CERN COURIER JULY/AUGUST 2019 9

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NEWS ANALYSIS NEWS ANALYSIS

Computing period of months in multiple locations. constant, respectively. the fine structure constant. “It appears The precision required is such that the “The revised SI future-proofs our to me as a conceptual weakness of the strength of the gravitational field, which measurement system so that we are n e w d e fi n it i o n s o f e l e c t r i c a l u n it s, e ven Computing boost for Lebanon and Nepal varies across the laboratory, must be ready for all future technological and if it does not have consequences for their measured before each trial. scientific advances such as 5G networks, practical use,” says Fayet. ita Bist D In the heart of Beirut in a five-storey be established at the government-run Once the required precision was quantum technologies and other inno- One way out of this, he suggests, is to house ow ned by t he Lebanese nat ional IT Park, with experts from Kathmandu achieved, the value of h could be fixed vations that we are yet to imagine,” says embed the new SI system within a larger

telecommunication company, floors University forming its core team. Rajen- a n d t h e d e fi n it i o n s i n v e r t e d, r e m o v i n g Richard Brown, head of metrology at framework in which c = ħ = μo = εo = 1, are about to be coated to make them dra Adhikari, project leader of Nepal’s the kilogram’s dependence on the IPK. the UK’s National Physical Laboratory. thereby fixing the vacuum magnetic anti-static, walls and ceilings will be HPC centre (pictured, second from right), Following several years of delibera- But the SI changes are controversial permeability and other characteristics i n s u l a t e d, a n d c a bl i n g s y s t e m s i n s t a l l e d a l s o w o n a n a w a rd f r o m N V I DI A for t h e tions, the new definition was formally The vacuum in some quarters. While heralding the of the vacuum (C. R. Physique 20 33). This so wires don’t become tangled. These latest graphics c a r d w or t h USD 3000 a n d adopted at the 26th General Conference magnetic n e w d e fi n it io n o f t h e k i l o g r a m a s “hu ge would allow all the units to be expressed a n d o t h e r d e t a i l s a r e s e t t o b e c o m pl e t e a d d e d it t o t h e s y s t e m. Ne p a l h a s n e v e r on Weights and Measures in November permeability progress”, CNRS research director Pierre in terms of the second, with the metre by mid-2020, when approximately had computing on such a scale before, l a s t y e a r. T h e 2019 r e d e fi n it io n o f t h e SI becomes Fayet warns of possible pitfalls of fix- and joule identified as fixed numbers 3000 pr o c e s s or c or e s, d o n a t e d b y C E R N, s a y s A d h i k a r i. “W it h t h i s f a c i l it y, w e c a n base units came into force in May, and a n u n fi xe d ing the value of the elementary charge: of seconds and reciprocal seconds, will arrive. t r a i n o u r s t u d e nt s a n d c o n d u c t r e s e a r c h also sees the ampere, kelvin and mole the vacuum magnetic permeability (μo) respectively. While likely attractive to The High-Performance Computing that requires high-performance com- redefined by fixing the numerical values parameter to t hen becomes a n un fi xed pa r a meter to high-energy physicists, however, Fayet for Lebanon (HPC4L) project is part of puting and data storage, from climate for the elementary , the be measured be measured experimentally, with the accepts that it may be some time before efforts by Lebanese scientists to boost modelling, earthquake simulations to Boltzmann constant and the Avogadro experimentally electrical units becoming dependent on such a proposal could be accepted. t he nat ion’s resea rc h c apabi l it ies. Li ke medical imag ing and basic researc h.” many other countries that have been T h e Ne p a l f a c i l it y i s pl a n n i n g t o s t or e AstrowAtch: white-dwArf merger through conflict and seen their high- health data from hospitals, which is ly-skilled graduates leave to seek bet- often deleted because of lack of storage ter oppor t un it ies, Leba non is t r y ing to space, and tests are being carried out Clocking the merger of two white dwarfs stem its brain-drain. Though the new to process drone images taken to map V Gvaramadse/Moscow University facilit y w ill not be t he only HPC cent re topography for hydropower feasibility A never-before-seen object with a cat- in the country, it is different because it Racking up e ffe c t i v e r u n n i n g o f t h e f a c i l it y. “We’v e studies. Even in the initial phases of the aclysmic past has been spotted in the involves both public and private insti- The HPC Nepal been working with the government, new centre, says Adhikari, computing constellation Cassiopeia, about 10,000 tutions and has the full support of the team in the private and public partners to prepare t a s k s t h a t u s e d t o t a k e 45 d a y s c a n n o w light years away. The star-like object government. “There are a few small- new computing not just the infrastructure but also the be processed in just 12 hours. has a temperature of 200,000 K, shines s c a l e H P C f a c i l it i e s i n d i ffe r e nt u n i v er- centre. t e a m,” e x pl a i n s H P C 4 L pr oj e c t c o ord i- The SESAME light source in Jordan, 40,000 times brighter than the and sities here, but they suffer from being nator Martin Gastal of CERN. “CERN/ which itself received 576 cores from is ejecting matter with velocities up to isolated and hence are quickly outdated C M S’s e x p e r t i s e a n d k n o w l e d g e w i l l h e l p CERN in 2017, is also using its experi- 16,000 km s–1. In combination with the a n d u n d e r u s e d,” s a y s p h y s i c i s t H a it h a m set up the facility and train users, but the ence to assist neighbouring regions in chemical composition of the surround- Z a r a k e t o f L e b a n e s e Un i v e r s it y i n B e i r ut. team in Lebanon will run it themselves.” setting up and maintaining HPC facil- ing nebula, the data indicate that it is the “T h i s H P C pr oj e c t p ut s t o g e t h e r t h e m a i n The Lebanese facility will also be used ities. “High-performance computing result of the merger of two dead stars. pl a y e r s i n t h e r e a l m o f H P C i n L e b a n o n.” for computational biology, oil and gas is a strong enabler of research capac- Astronomers from the University of H a v i n g j oi n e d t h e L HC’s C M S e x p e r i- discovery, financial forecasting, genome ity building in regions challenged by Bonn and Moscow detected the unu- m e nt i n 2016, L e b a n e s e p h y s i c i s t s w a nt analysis and t he social sciences. limited financial resources and talent sual object while searching for circum- Rejuvenated star Infrared images show the result of the merger of two white dwarfs. to develop the new facility into a CMS Nepal is another country striving e x o d u s,” s a y s G a s t a l. “B y s u p p or t i n g t h e stellar nebulae in data from NASA’s Tier-2 computing centre. High-speed for greater digital storage and com- set up of efficient data processing and Wide-Field Infrared Survey Explorer matter from a nearby companion star, supernova, but there are also models in internet will connect it to universities puting power. In 2017 Nepal signed a storage facilites, CERN, together with satellite. Memorably named J005311, it can become hot enough to restart the which carbon is ignited in a more subtle a r o u n d t h e w orl d a n d H P C 4 L h a s a m a n- cooperation agreement with CERN. affiliated institutes, can assist fellow and measuring about five light years fusion of carbon into heavier elements. way during the merging process, allow- d a t e t o e n s u r e o p e r a t i o n, m a i nt e n a n c e, The following year, around 2500 cores r e s e a r c h e r s i n i n v e s t i n g i n t h e s c ie nt i fic across, it barely emits any optical light This process is so violent that the radia- ing it to start fusing without blowing and user-interfacing for smooth and from CERN enabled an HPC facility to potent ial of t heir ow n count ries.” and radiates almost exclusively in the tion pressure it produces blows the star the newly formed object apart. J005311’s infrared. Additionally, the matter it apart. Such “type 1A” supernovae are detection appears to indicate that those C Suplee/NIST Si unitS Weighing in the second and the metre are defined emits consists mostly of oxygen and observed frequently and, since they are models are correct, marking the first The NIST-4 Kibble in terms of a hyperfine transition in does not have any signs of hydrogen or unleashed when a white dwarf reaches a observation of a white-dwarf merger. Kilogram joins balance contributed caesium-133 and the speed of light, helium, the two most abundant mate- very specific mass, they have a standard The rejuvenated star is, however, to an international knowledge of h allows the kilogram to rials in the universe. All this makes it brightness that can be used to measure not expected to live for long. Based the ranks of effort to define all be set without reference to the IPK. unlike a normal massive star and more cosmic distances. on the models it will burn through its base units in terms Measuring h to a suitably high pre- in line with a white dwarf. Despite having the chemical signature remaining fuel within 10,000 years or reproducible units of fundamental cision of 10 parts per billion required White dwarfs are “dead stars” that of a white dwarf, such an object can- so, forming a core of iron that is set to constants. decades of work by international teams remain when typical stars have used not possibly burn as bright as J005311. collapse into a neutron star through a O n 20 M a y, 1 4 4 y e a r s a f t e r t h e s i g n i n g o f a c r o s s c o nt i n e nt s. I n 1975 Br it i s h p h y s- up all of their hydrogen and helium By comparing the characteristics of v i ol e nt e v e nt a c c o m p a n i e d b y a fl a s h o f t h e M e t r e C o n v e nt i o n i n 1875, t h e k i l o - icist Bryan Kibble proposed a device, fuel, at which point the oxygen- and J005311 with models of what happens and possibly a gamma-ray g r a m w a s g ive n a ne w d e fi n it ion b a s e d t hen k now n as a w at t ba lance and now carbon-rich star collapses into itself to when two white dwarfs merge, however, burst. Using the speed of the ejected on Planck’s constant, h. L o n g t i e d t o t h e r e n a m e d t h e K i b bl e b a l a n c e i n h i s h o n- form a high-mass Earth-sized object. the explanation falls into place. As two material and the distance it has reached International Prototype of the Kilogram our, which linked h t o t h e u n it o f m a s s. A The white dwarf is kept from further white dwarfs, likely produced billions from the star by now, it can be calculated (IPK) – a platinum-iridium c ylinder in c oi l i s pl a c e d i n s i d e a pr e c i s e l y c a l i br a t e d collapse into a neutron star only by the of years ago, orbited one another they that the merger took place about 16,000 Paris – the kilogram is the last SI base magnetic field and a current driven electron degeneracy pressure of the slowly lost momentum through the y e a r s a g o, m e a n i n g t h a t it s fi n a l c ol l a p s e u n it t o b e r e d e fi n e d b a s e d o n f u n d a men- t h r o u g h it s u c h t h a t a n e l e c t r o m a g n e t i c elements in its core, and its tempera- emission of gravitational waves. Over is not far away. tal constants or atomic properties rather force on the coil counterbalances the ture is too low to enable further fusion. time, the objects came so close to each t han a -made ar tefact. for c e o f g r a v it y. T h e e x p e r i m e nt i s t h e n However, if the mass of the white dwarf other that they merged. This would com- Further reading s The dimensions of h a r e m 2 k g s –1. Si n c e repeated thousands of times over a increases, for example if it accretes monly be expected to produce a type 1A V Gvaramadze et al. 2019 Nature 569 684.

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Best Cyclotron Systems provides 15/20/25/30/35/70 MeV DIGEST Proton Cyclotrons as well as 35 & 70 MeV Multi-Particle (Alpha, Deuteron & Proton) Cyclotrons

Currents from 100uA to 1000uA (or higher) depending on the (arXiv:1905.13704). Meanwhile, the excites the quantum vacuum and cavities: would be con- particle beam are available on all BCS cyclotrons BESIII e+e– experiment in Beijing gives rise to the emission of quanta, verted to in the magnetic has published 3.9σ evidence for its known as Hawking radiation. The field of a gapped toroid inspired ± Best 20u to 25 and 30u to 35 are fully upgradeable on site decay to ρ ηc (arXiv:1906.00831). group now plans to study the time by the ABRACADABRA and DM The Zc resonance’s quark con- evolution of the analogue BH. Radio experiments (arXiv:1904. figuration is still unknown, 0724). Meanwhile, cosmologist Cyclotron Energy (MeV) Isotopes Produced with models to describe its inner In pursuit of Majorana Lawrence Krauss proposes to M Br ice/CER N-PHO T O-201611-278-2 18F, 99mTc, 11C, 13N, 15O, structure including loosely bound Researchers working on EXO-200 use atomic clocks to look for the Best 15 15 64Cu, 67Ga, 124I, 103Pd of charm- – a prototype liquid-xenon TPC in effect of an background pairs, compact , and Carlsbad, New Mexico – are step- on photon propagation in the Best 15 + 123I, Best 20u/25 20, 25–15 hadro-. ping up their pursuit of neutrino- vacuum (arXiv:1905.10014). Sim- 111In, 68Ge/68Ga less double (0νββ): the ilarly inventive proposals pub- Strange neutron stars most sensitive probe for the pos- lished recently seek to extend 123 Best 30u Best 15 + I, Researchers working on the STAR tulated Majorana nature of neutri- the search for generic low-mass 30 111 68 68 (Upgradeable) In, Ge/ Ga The NA64 experiment. detector at BNL’s Relativistic nos, whereby a neutrino is its own dark matter downwards, for exam- Greater production of Heavy-Ion Collider have measured . The full EXO-200 data ple using nuclear recoils in lab- Through a beam dump darkly the binding energy of hypertriton s e t a l l o w e d a 90% c o n fid e n c e l i m it grown diamond crystals (Phys Rev Best 35 35–15 Best 15, 20u/25 isotopes The NA64 collaboration at CERN has – a hypernucleus consisting of a on the half life of 0νββ in 136Xe of D 99 123005). 201 81 81 plus Tl, Rb/ Kr published world-best limits on dark proton, neutron and Λ . 3.5 × 1025 years (arXiv:1906.02723), 82 82 123 67 photons below a mass of 200 MeV, They found a higher value than approaching the world-best limit EDM search goes pear-shaped Sr/ Rb, I, Cu, Installation of Best 70 MeV 25 Best 70 70–35 81 excluding mixing strengths down to the accepted 1973 measurement, of 10.7 × 10 years set by KamLand– Permanent electric dipole Kr + research –3 –5 Cyclotron at INFN, Legnaro, 10 , and below 10 for masses of the calling weakly-bound Λ-deuteron Zen in 2016. Comparable limits in moments (EDMs) of particles are order of 1 MeV (arXiv:1906.00176). models of the particle into ques- other isotopes where single-beta excellent testbeds for the Standard Hypothetical dark-sector physics tion (arXiv:1904.10520). The team decay is suppressed have been set Model. Nonzero EDMs imply that could have an equally rich struc- has also provided new constraints for 76Ge (8.0 × 1025 years, GERDA) both P and T, and by implication ture as the Standard Model, and the on neutron-star interiors (see also and 130Te (1.5 × 1025 years, CUORE). dark-photon vector field is one pos- p16) and reported the first test of Attention is now turning to nEXO, a sible extension that could mix with matter– symmetry per- planned tonne-scale successor that The BG-75 Biomarker Generator is a revolutionary 400 MeV Rapid Cycling Medical Synchrotron the photon. A fixed-target exper- taining to the binding of strange will push the sensitivity up by two development in radio-pharmaceutical production for Proton-to-Carbon Heavy Ion Therapy: iment at CERN’s SPS, NA64 (image quarks in a nucleus. orders of magnitude to ~1028 years. that delivers a single or batch dose of 18F-FDG, and above) looks for missing energy in the interaction of 100 GeV electrons Hawking’s maths vindicated The rarest decay 18 Intrinsically small beams facilitating additional advanced F biomarkers on demand. beam delivery with precision in an active beam dump. Following the first observation of The XENON1T experiment, located The system provides integration of all components Hawking radiation in 2016 (Nature 1.4 km below the Gran Sasso massif needed to produce and qualify PET biomarkers Small beam sizes – small magnets, Circular reasoning Phys. 12 959), researchers at the in northern Italy, has observed the light gantries – smaller footprint Following the European Strategy Israeli Institute of Technology have rarest decay process ever seen, with Nuclei with octupole distortions may into a single, self-contained system that occupies Update in Granada (see p7), pro- now quantitatively confirmed the a half-life a trillion times longer bear fruit in EDM searches. a fraction of the space required by conventional Highly efficient single turn extraction ponents of a 100 km future circular thermality of its spectrum and than the age of the universe: the collider in the vicinity of CERN have measured its temperature using two-neutrino double-electron CP, are violated. Nuclear physicists solutions, simplifying the implementation of PET. 124 Efficient extraction – less shielding released a “Frequently Asked Ques- an analogue black hole (BH) con- capture of Xe (Nature 568 532). have thus been seeking to measure tions”-style document, which will sisting of a flowing Bose–Einstein The measurement is a step towards atomic EDMs since the 1980s, with Flexibility – heavy ion beam therapy be regularly updated as the com- condensate (Nature 569 688). The the search for neutrinoless dou- pear-shaped nuclei the most prom- ( and/or carbon), beam munity debates the post-LHC future flow is supersonic within the ana- ble-electron capture, which, like ising candidates. More correctly delivery modalities (arXiv:1906.02693). Focused on the logue BH and subsonic without: neutrinoless double-beta decay, termed a static octupole distor- fi r s t “F C C- e e” p h a s e, t h e d o c u m e nt the event horizon at the boundary would establish the Majorana t i o n, t h e p e a r s h a p e w a s fi r s t s e e n currently addresses 24 questions, nature of the neutrino and give at CERN’s ISOLDE facility in radi- including “Why do we need at least access to the absolute neutrino um-isotope 224Ra in 2013 (Nature

5 × 1012 Z decays?”, “Why do we want Technion mass. The detector’s active mass 497 199). However, Peter Butler FCC in Europe?” and quite simply is now being trebled to boost its of the University of Liverpool and “Are there better ways to 100 TeV primary dark-matter search. coworkers, using beams from the than FCC-ee?” upgraded HIE-ISOLDE, have now ion Rapid Cycling Medical Got an axion to grind? established that radon-isotopes ± 224 226 Synchrotron (iRCMS) Dø nabs Zc(3900) Researchers are turning to cre- Rn and Rn do not possess Following first observations of the ative proposals to search for static pear shapes in their ground ± charmonium-like state Zc(3900) at axions – cold dark-matter can- states, and are thus not promis- e+e– colliders in 2013, the Dø col- didates originally postulated to ing candidates to have measura- laboration has published 5.4σ evi- resolve the strong CP problem in ble atomic EDMs (Nat. Commun. 10 TeamBest Companies © 2019 * Best iRCMS is under development and not available for sale currently. dence for its presence in the decay Jeff Steinhauer’s group has measured QCD. Berkeley theorists propose 2473), inducing the team to switch – www.bestcyclotron.com • www.bestabt.com • www.bestproton.com chain of b-quarks in pp collisions the Hawking temperature. employing superconducting RF focus to other isotopes.

BCS tel: 604 681 3327 • Best ABT tel: 865 982 0098 • BPT tel: 703 451 2378 CERN COURIER JULY/AUGUST 2019 13

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Reports from the experiments LHCb Three-body B+ decays violate CP

New sources of CP violation (CPV) 0.8 are needed to explain the absence of + 100 B data antimatter in our matter-dominated B+ model 0.6 universe. The LHCb collaboration has B– data reported new results describing CPV in B– model B+ → π+K+K– and B+ → π+π+π– decays. Until 80 0.4 ) ) 4 very recently, all observations of CPV 2 /c in B mesons were made in two-body 2 0.2 and quasi-two-body decays; however, 60 it has long been conjectured that the 0 complex dynamics of multi-body decays could give rise to other manifestations. 40 –0.2 For CPV to occur in B decays, compet- entries/(0.0675 GeV ing decay amplitudes with different asymmetry/(0.03 GeV/c weak phases (which change sign under –0.4 CP) and strong phases (which do not) 20 cos θhel > 0 are required. The weak phase differ- –0.6 cos θhel < 0 ences are tied to fundamental param- eters of the Standard Model (SM), but 0 –0.8 the strong phase difference can arise 1 2 3 0.6 0.8 1.0 1.2 1.4 from loop-diagram contributions, 2 + – 2 4 2 m K K (GeV /c ) mπ+π– (GeV/c ) final-state re-scattering effects, and phases associated with intermediate Fig. 1. Left: yields of B+ → π+K+K– and B– → π–K–K+ showing a clear asymmetry in the region of phase space resonant structure. dominated by re-scattering effects. Right: the CP asymmetry between +B → π+π+π– and B– → π–π–π+ decays in a 0 The three-body B decays under study region of phase space including the ρ(770) and f2(1270), divided according to whether the cosine of the helicity

proceed mainly via various intermedi- angle is positive (blue) or negative (red). (cosθhel > 0 if, in the rest frame of the B, the with the same charge ate resonances – effectively, a cascade as the B has higher momentum than its oppositely charged counterpart.) The bands indicate the full spread of of two-body decays – but also include the isobar, K-matrix and quasi-model-independent models used to describe the decays. contributions from non-resonant three-body interactions. The phase to accurately model the complex S-wave of an amplitude analysis, found in the space is two-dimensional (it can be component of the decays, which is the ππ ↔ KK re-scattering amplitude; the fully described by two kinematic c o n fi g u r a t i o n w h e r e t h e r e i s n o r e l ative first observation of CPV in the interfer- variables) and its size allows a rich angular momentum between a pair of ence between intermediate states, seen tapestry of resonant structures to oppositely-charged final-state particles, in the overlap between the dominant emerge, bringing quantum-mechan- and which contains broad resonances spin-1 ρ(770) 0 resonance and the π+π+ ical interference into play. Much as in t hat a re d i ffic ult to model. Th ree com- S-w a v e; a n d t h e fi r s t o b s e r v a t io n o f C PV Young’s double-slit experiment, the plementary approaches were deployed to involving a spin-2 resonance of any kind, + + total amplitude comprises the sum of describe the complicated spin-0 S-wave found in the decay B → f2(1270)π . These all possible decay paths. The interference component of the B+ → π+π+π– decay: r e s u l t s pr o v i d e s i g n i fic a nt n e w i n s i g ht s pattern and its phase variation could the classical isobar model, which into how CPV in the SM manifests in contribute to CPV in regions where res- explicitly associates a line-shape with practice, and motivate further study, onances overlap. a clear physical interpretation to each particularly into the strong-phase- One of the most intriguing LHCb contribution in the phase space; the generating QCD processes that govern results was the 2014 observation of K-matrix method, which takes data CP violation. l a r g e C P V e ffe c t s i n c e r t a i n p h a s e-s p ace This is from scattering experiments as an input; regions of B+ → π+K+K– and B+ → π+π+π– the first and finally a quasi-model-independent Further reading d e c a y s. I n t h e n e w a n a l y s i s, t h e s e e ffe c t s observation approach, in which the S-wave magni- LHCb Collaboration 2014 Phys. Rev. D 90 are described with explicit amplitude of CP violation tude and phase are extracted directly 112004. models for the first time (figure 1). A in the from the data. LHCb Collaboration 2018 LHCb-PAPER- crucial step in the phenomenological LHCb’s amplitude analyses of these 2018-051. interference description of these amplitudes is to decays are based on data from Run 1 of LHCb Collaboration 2019 LHCb-PAPER- include unitarity-conserving couplings between the LHC and contain several ground- 2019-017. between final states, most notablyππ intermediate breaking results, including the largest LHCb Collaboration 2019 LHCb-PAPER- a n d K K . A c c o u nt i n g for t h e s e i s e s s e nt i a l states CP asymmetry in a single component 2019-018.

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ENERGY FRONTIERS ENERGY FRONTIERS

ALICE away from each other and combine with cross-section ratio in pp-collisions The results contribute significantly to charm newly generated quarks. In heavy-ion (figure 1) is found to be significantly highlight hadron production in this pT range Studying neutron stars in the laboratory collisions, hadron production can also larger than that calculated in the the lack of for PbPb collisions. These are the first occur via “coalescence”, whereby charm standard version of the popular measurements of the ratios at high pT quarks combine with other quarks Monte-Carlo event generator PYTHIA, understanding for both the pp and PbPb systems at Neutron stars consist of extremely Data from proton–lead collisions at while traversing the QGP. The contri- while the inclusion of an improved of charm– a –nucleon centre-of-mass dense nuclear matter. Their maximum 2.6 a centre-of-mass energy per nucleon bution of coalescence depends strongly description of the fragmentation quark energy of 5.02 TeV. – size and mass are determined by their ALICE p–Pb √s NN = 5.02 TeV pair of 5.02 TeV show that p-Ξ pairs on the transverse momentum (pT) of (“PYTHIA8+CR”) can better describe hadronisation In late 2018, CMS collected data cor- equation of state, which in turn depends – – + are produced at very small distances the , and is expected to be the CMS data. The data can also be rea- responding to about 10 times more PbPb p-Ξ ⊕ p-Ξ in proton– on the interaction potentials between 2.2 (~1.4 fm); the measured correlation is much more significant for charm sonably described by a different model collisions than were used in the cur- + proton . Due to the high density, not Coulomb + HAL-QCD therefore sensitive to the short-range than for charm mesons, as they that includes Λc baryons produced by rent measurement. These will shed new only but also heavier strange . The measured contain more quarks. the decays of excited charm baryons collisions light on the interplay between the Coulomb – baryons may play a role. ) p-Ξ correlations were found to be The CMS experiment has recently (dashed line). However, an attempt to different processes in charm–quark * 1.8 The main experimental information p-Ξ– sideband background stronger than theoretical correlation determined the Λ+/D0 yield ratio over incorporate the coalescence process hadronisation in heavy-ion collisions.

C(k c + – + on the interaction potentials between functions with only a Coulomb inter- a broad range of pT using the Λc → pK π characteristic of hadron production In the meantime, the current results 0 – + nucleons and strange baryons comes 1.4 action, whereas the prediction obtained and D → K π decay channels in both in heavy-ion collisions (solid line) highlight the lack of understanding from bubble-chamber scattering exper- by including both the Coulomb and pp and lead–lead (PbPb) collisions, at fails to reproduce the pp-collision of charm–quark hadronisation in pp iments with strange-hadron beams strong interactions (as calculated by the a nucleon–nucleon centre-of-mass measurements. collisions, a subject that requires fur- undertaken at CERN in the 1960s, and HAL-QCD collaboration) agrees with the energy of 5.02 TeV. Comparing the The CMS collaboration also measured ther experimental measurements and 1.0 + 0 + is limited in precision due to the short data (fig ure 1). behaviour of the Λc/D ratio in differ- Λc production in PbPb collisions. The theoretical studies. + 0 lifetimes (< 200 ps) of the hadrons. As a first step towards evaluating ent collision systems allows physicists Λc/D -production ratio for pT > 10 GeV/c The ALICE collaboration is now using 0 100 200 300 the impact of these results on mod- to study the relative contributions of is found to be consistent with that from Further reading the scattering between particles pro- k* (MeV/c) els of neutron-star matter, the HAL- fragmentation and coalescence. pp collisions. This similarity suggests CMS Collaboration 2019 arXiv:1906. + 0 duced in collisions at the LHC to con- QCD interaction potential was used to The measured Λ c/D -production that the coalescence process does not 03322. strain interaction potentials in a new Fig. 1. p-Ξ– correlation as a function of the relative momentum compute the single-particle potential way. So far, pK–, pΛ, pΣ0, pΞ– and pΩ– of the proton and Ξ–, and the expected background contribution. of Ξ– within neutron-rich matter. A ATLAS interactions have been investigated. The models show theoretical predictions, including only the slightly repulsive interaction was Recent data have already yielded the Coulomb interaction, and both the Coulomb and strong inferred (of the order of 6 MeV, com- – How many protons collided in ATLAS in Run 2? first evidence for a strong attractive interaction, as computed within the lattice–QCD framework of pared to the 1322 MeV mass of the Ξ ), interaction between the proton and the HAL-QCD collaboration. leading to better constraints on the the Ξ– baryon. equation of state for dense hadronic The large amount of Run-2 data (collected 20–50 interactions per crossing, and the Strong final-state interactions Ξ– particles as a function of their relative systems that contain Ξ– particles. in 2015–2018) allows the LHC experi- 5 pattern of proton bunches changes from between pairs of particles make their momentum (the correlation function) This is an important step towards ments to probe previously unexplored 4 ATLAS preliminary isolated bunches to trains of consec- momenta more parallel to each other and comparing it with theoretical cal- determining the equation of state for rare processes, search for new physics √s = 13 TeV utive bunches with 25 ns spacing. The 3 in the case of an attractive interaction, c u l a t io n s b a s e d o n d i ffe r e nt i nt e r a c t i o n dense and cold nuclear matter with and improve Standard Model measure- reference fill 6931, July 16, 2018 LUCID-2 response is sensitive to these and increase the opening angle between potentials. This technique is referred to strange hadrons. ments. The amount of data collected in 2 differences. It is corrected with the help them in the case of a repulsive interac- as “femtoscopy” since it simultaneously R u n 2 c a n b e q u a nt i fie d b y t h e i nt e g r a ted 1 of a track counting algorithm, which – tion. The attractive potential of the p-Ξ measures the size of the region in which Further reading luminosity – a number which, when mul- –1 (%) 0 relates the number of interactions to interaction was observed by measuring particles are produced and the interac- ALICE Collaboration 2019 tiplied by the cross section for a process, the number of tracks reconstructed in LUCID-2 the correlation of pairs of protons and tion potential between them. arXiv:1904.12198. yields the expected number of interac- –1 ATLAS’s inner detector. L/L tracking tions of that type. It is a crucial figure. –2 The final step is to monitor the sta- CMS EMEC The uncertainty of several ATLAS Run-1 –3 FCal bility of the LUCID-2 calibration over cross-section measurements, particu- time. This is evaluated by comparing –4 TILE New constraints on charm–quark hadronisation larly of W and Z production, was domi- the luminosity estimate of LUCID-2 to nated by systematic uncertainty on the –5 those from track counting in the inner integrated luminosity. To minimise 0 0.2 0.4 0.6 0.8 1.0 detector and various ATLAS calorime- + 0 One of the most useful ways to under- Fig. 1. The Λc/D this, ATLAS performs precise absolute luminosity fraction ters over the course of the data-taking PbPb 44 μb–1, pp 38 nb–1 (5.02 TeV) stand the properties of the quark–gluon production 0.7 and relative calibrations of several lumi- y e a r (fi g u r e 1). T h e a g r e e m e nt b e t w e e n plasma (QGP) formed in relativistic cross-section ratio CMS pp nosity-sensitive detector systems in a Fig. 1. Fractional difference in the luminosity estimates of d e t e c t or s q u a nt i fie s t h e s t a bi l it y o f t he heavy-ion collisions is to study how versus transverse 0.6 |y| < 1.0 data three-step procedure. LUCID-2 compared with track counting, and the ATLAS LUCID-2 response. various probes interact when propa- momentum for pp PbPb PYTHIA8 The first step is an absolute calibration electromagnetic end-cap (E M EC), for ward (FCal) and hadronic Using this three-step method and gating though it. Heavier quarks, such and PbPb collisions, 0.5 data: cent. 0–100% PYTHIA8 + CR of the luminosity using a van-der-Meer tile (TILE) calorimeters in 2018. This long-term behaviour is taking into account correlations ) as charm, can provide unique insights with predictions 0 EPJC 78 348 beam-separation scan under special- used to quantify the uncertainty in the LUCID-2 calibration between years, ATLAS has obtained a

as they are produced early in the col- from various + D arXiv:1902.08889 ised beam conditions. By displacing the stability over time, indicated by the yellow band. preliminary uncertainty on the lumi- 0 0.4 lisions, and their interactions with the pp-collision beams horizontally and vertically and nosity estimate for the combined Run-2 ) / (D – QGP differ from their lighter cousins. models. c 0.3 scanning them through each other, it is of photomultiplier tubes located 17 m in data of 1.7%, improving slightly on the One important input to these studies is possible to measure the combined size either direction along the beam pipe that Run-1 precisions of 1.8% at 7 TeV and + Λ + a detailed understanding of hadronisa- c 0.2 of the colliding proton bunches. Deter- detect the Cherenkov light of particles The 1.9% at 8 TeV. The full 13 TeV Run-2 data ( Λ tion, by which quarks form experimen- mining in addition the total number of which come from the interaction – the uncertainty of sample corresponds to an integrated –1 16 tally detectable mesons and baryons. 0.1 protons in each colliding bunch from scale for the absolute luminosity meas- several Run-1 luminosity of 139 fb – about 1.1 × 10 The lightest charm baryon and meson the measurement of the beam currents, urement of LUCID-2 is set. proton collisions. + 0 – measurements are the Λc (udc) and the D (cu). In proton– 0 the absolute luminosity of each collid- The second step is to extrapolate proton (pp) collisions, charm hadrons 4 6 8 10 12 14 16 18 20 ing bunch pair can be derived. Relating this calibration to LHC physics condi- was dominated Further reading are formed by fragmentation, in which P (GeV/c) this to the mean number of interactions tions, where the number of interactions by the ATLAS Collaboration 2019 ATLAS-CONF-

s T charm quarks and antiquarks move observed in the LUCID-2 detector – a set increases from fewer than one to around luminosity 2019-021.

16 CERN COURIER JULY/AUGUST 2019 CERN COURIER JULY/AUGUST 2019 17

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Performing a STOP FIELD analysis requires NOTES a multiphysics Reports from events, conferences and meetings

approach... Royal Society Hooke meeting

Structural-thermal-optical performance (STOP) Topological avatars of new physics analyses involve temperature calculation, structural deformation modeling, and ray Topologically non-trivial solutions of sou it M V peratures and strong magnetic fields of tracing. To perform a STOP analysis, engineers quantum field theory have always been heavy-ion collisions at the LHC. David need to account for all of these physics in one a theoretically “elegant” subject, cov- Tong discussed the ambiguities on the ering all sorts of interesting and physi- gauge group of the Standard Model, and high-fidelity simulation. With the COMSOL® cally relevant field configurations, such how these could affect monopoles that are software, you can. as mag net ic monopoles, spha lerons a nd admissible solutions of such gauge field bl a c k h ol e s. T h e s e o bj e c t s h a v e pl a y e d a n t h e o r i e s. I m p o r t a nt l y, s u c h s olut i o n s g i v e Visualization of ray The COMSOL Multiphysics® software is used i mp or t a nt role i n s h a pi n g q u a nt u m fie ld rise to potentially observable phenom- trajectories for three field for simulating designs, devices, and processes theories and have provided important ena at the LHC and at future colliders. angles in a Petzval lens in all fields of engineering, manufacturing, and p h y s ic a l i n s i g ht s i nt o c o s m ol o g y, p a r t ic l e Anna Achucaro and Tanmay Vachaspati system at nonuniform scientific research. See how you can apply it to colliders and condensed-matter physics. reported on fascinating computer simu- temperature. STOP analysis. I n l a y m a n’s t e r m s, a fie l d c o n fi g u r a t io n l a t i o n s o f m o n o p ol e s c a t t e r i n g, a s w e l l a s is topologically non-trivial if it exhibits numerical studies of cosmic strings and comsol.blog/STOP-analysis t h e t o p ol o g y o f a “m a t h e m a t i c a l k n o t” i n o t h e r t o p ol o g i c a l l y n o n-t r i v i a l d e fe c t s o f some space, real or otherwise. A math- relev ance to cosmolog y. ematical knot (or a higher-dimensional t i v i s t ic q u a nt u m fie l d t h e or ie s i n p a r t ic le Spatial awareness One of the exemplars of topological generalisation such as a Möbius strip) is p h y s i c s, g e n e r a l r e l a t i v it y a n d c o s m ol o g y, Gerard ’t Hooft physics currently receiving significant n o t l i k e a r e g u l a r k n o t i n a pie c e o f s t r i n g: a n d q u a nt u m g r a v it y. O f p a r t i c u l a r i nt e r e s t grapples with experimental attention is the magnetic it h a s n o e n d s a n d c a n n o t b e c o nt i nu o u s l y w e r e t o p ol o g i c a l o bj e c t s t h a t c o u l d p o t e n- the quantum monopole. The MoEDAL experiment at the deformed into a topologically trivial con- tially be detectable at the Large Hadron mechanics of LHC has reported world-leading limits on fig urat ion li ke a circle or a sphere. Collider (LHC), or at f ut ure colliders. black holes. multiply magnetically charged monopoles, One of the most conceptually sim- a n d A l b e r t d e R o e c k g a v e a w i d e-r a n g i n g ple non-trivial configurations arises in Black holes and r e p or t o n t h e s e a r c h for t h e m o n o p ol e a n d SUPERCON, Inc. the classification of solitons, which are G e r a rd ’t Ho o f t o p e n e d t h e s c i e nt i fic pr o - o t h e r h i g h l y-i o n i s i n g p a r t i c l e s, w it h L a u r a fi n it e- e n e r g y e x t e n d e d c o n fi g u r a t i o n sof c e e d i n g s w it h a n i n s pi r i n g t a l k o n for m- Patri zii and Adrian Bev an also repor ting Superconducting Wire and Cable a scalar field behaving like the Higgs field. ulating a black hole in a way consistent o n t h e s e s e a r c h e s a n d t h e m a c h i n e-l e a r n- Among the various finite-energy clas- with and time- ing techniques employed in them. sical solutions for the Higgs field, there r e v e r s a l s y m m e t r y, b e for e St e v e n G i d d i n g s Supersymmetric scenarios can con- Standard and Specialty designs are available to meet your most demanding are some that cannot be continuously d e s c r i b e d h i s e q u a l l y i nt e r e s t i n g pr o p o s a l. sistently accommodate all the afore- superconductor requirements. deformed into the vacuum without an A n o t h e r h i g h l i g ht w a s Ni c h ol a s M a nt o n’s mentioned topologically non-trivial field i n fi n ite cost i n energ y, a nd a re t here fore talk on the inevitability of topological theory configurations. Doubtless, as John SUPERCON, Inc. has been producing niobium-based superconducting wires and cables for half a century. “stable”. For finite-energy configurations non-trivial unstable configurations of the E l l i s d e s c r i b e d, t h e s t or y o f t h e s e a r c h for the original SUPERCON t h a t a r e s p h e r i c a l l y s y m m e t r i c, t h e H i g g s Higgs field – “sphalerons” – in the Stand- this beautiful – but as yet hypothetical We are – the world’s first commercial producer of niobium-alloy based wire and field must map smoothly onto its vacuum a r d M o d e l. He n r y T y e s a i d s p h a l e r o n s c a n – n e w s y m m e t r y o f n at u r e, i s a lo n g w a y cable for superconducting applications. solut ion at t he boundar y of space. in principle be produced at the (upgraded) from being over. Last but not least, were T h e ’t Ho o f t–P ol y a k o v m o n o p ol e, w h i c h LHC or future linear colliders. A contra- t w o i n s pi r i n g t a l k s b y Ju a n G a r c i a B e l l id o Standard SC Wire Types Product Applications i s pr e d i c t e d t o e x i s t i n g r a n d u n i fie d t h eo - d ic t or y v ie w w a s t a k e n b y S e r g e i D e m id o v, and Marc Kamionkowski on the role of NbTi Wires Magnetic Resonance Imaging r ies, is one suc h fin ite-energ y topolog i- who predicted that their production will primordial black holes as dark matter, cally non-trivial solitonic configuration. be strongly suppressed at colliders. and their potential detection by means Nb3Sn —Bronze Nuclear Magnetic Resonance T h e bl a c k h ol e i s a n e x a m pl e f r o m g e n e r a l A major part of the workshop was of g rav itat ional w aves. Nb3Sn —Internal Tin High Energy Physics relativity of a singular space–time con- devoted to monopoles. The theoretical The workshop ended with a vivid CuNi resistive matrix wires SC Magnetic Energy Storage figuration with a non-trivial space–time framework of light monopoles within r o u n d-t a bl e d i s c u s s i o n o f t h e i m p or t a n c e Fine diameter SC Wires Medical Therapeutic Devices topology. The curvature of space–time t he St a nda rd Mo de l, p ossibly pro duc ible One of the o f a n e w ~100 TeV collider. The aim of this blows up in the singularity at the cen- at the LHC, was presented by Yong Min m a c h i n e i s t o e x pl or e b e y o n d t h e h i s t or i c Aluminum clad wire Superconducting Magnets and Coils t r e, a n d t h i s c a n n o t b e r e m o v e d e it h e r b y Cho. These “electroweak” monopoles exemplars of w a t e r s h e d r e pr e s e nt e d b y t h e d i s c o v e r y o f Wire-in-Channel Crystal Growth Magnets continuous deformations or by coordinate have t w ice t he mag net ic charge of Dirac topological t h e H i g g s b o s o n, a n d t o m o v e u s c l o s e r t o Innovative composite wires Scientific Projects c hanges: its nat ure is topolog ical. monopoles. Like the ’t Hooft–Polyakov physics understanding the origin of elementary Such configurations constituted the monopole, but unlike the Dirac mono- receiving particles, and indeed space–time itself. m a i n t h e m e o f a r e c e nt R o y a l S o c ie t y Ho o k e pole, they are solitonic structures, with significant This Hooke workshop clearly demon- “We deliver superconductivity!” m e e t i n g “To p ol o g ic a l a v a t a r s o f n e w p h y s- the Higgs field playing a crucial role. experimental strated the importance of topological i c s”, w h i c h t o o k pl a c e i n L o n d o n f r o m 4–5 Arttu Rajantie considered relatively av atars of new physics to suc h a project. M a r c h. T h e m e e t i n g fo c u s e d o n t h e or e t i c a l unsuppressed thermal production of attention is Contact us at [email protected] m o d e l l i n g a n d e x p e r i m e nt a l s e a r c h e s for generic monopole–antimonopole pairs the magnetic Nick Mavromatos King’s College www.SUPERCON-WIRE.com t o p ol o g i c a l l y i m p or t a nt s olut i o n s o f r e l a- i n t h e pr e s e n c e o f t h e e x t r e m e h i g h t e m- monopole and James Pinfold University of Alberta.

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FIELD NOTES FIELD NOTES

IPAC 2019 CERN–LatiN-a mERiCaN SChooL of high-ENERgy PhySiCS Accelerator community comes together in Melbourne High-energ y physics flourishes in Lat in A merica N Harrison More than 1100 accelerator professionals “In Unity” was chosen as the theme M Mulders gathered in Melbourne, Australia, from 19 for IPAC’19 and art was commissioned The 10th edition of the CERN–Latin- to 24 May 2019 for the 10th International from Torres Strait islander Kelly Say- American School of High-Energy Particle Accelerator Conference, IPAC’19. lor to symbolise this coming together Physics (CLASHEP) hosted 75 students The superb Melbourne Convention and of the particle-accelerator community. from 13 to 26 March in Villa General Exhibition Centre could easily cater for the The success of IPAC’19 demonstrates the Belgrano in the Argentinian province 85 s c i e nt i fic t a l k s, 72 i n d u s t r i a l e x h i bit or s ongoing need for face-to-face meetings of Cordoba. CLASHEP is a biennial series and sponsors, 1444 poster presentations to share and communicate ideas and col- that takes place in different Latin- and several social functions through- l a b or a t e o n pr e s s i n g s c i e nt i fic pr o bl e m s. American locations. Since the first out the week. Record levels of diversity I n a pi o n e e r i n g e ffor t for t h e I PAC s e r i e s, school in 2001, there has been a dra- at IPAC’19 saw 42 countries represented the opening and closing sessions were matic increase in the involvement of from six continents, and a relatively high live-streamed to the world. The aim is Latin-American groups in experi- gender balance for the field, with a quarter to broaden the impact of the conference mental HEP, including collaboration of spea kers ident i f y ing as women. and highlight the importance of particle in the ALICE, ATLAS, CMS and LHCb In t he w a ke of t he update of t he Euro- accelerators to many fields of science, experiments at CERN. The schools have pean Strategy for Particle Physics in Australian I V light source ta k ing cent re stage. industry and medical applications. played an important role in fostering Granada in May, accelerator designs that expertise Exciting progress in the field of Student poster prizes were won by this increased interest and participation advance the energy and intensity range of Suzie Sheehy plasma- wakefield accelerators was Nazanin Samadi, an Iranian PhD stu- in HEP in the region, as well as rein- a next-generation discovery machine were sizes up future also reported. In particular, Europe’s dent at the University of Saskatchewan, forcing existing activities and training discussed, but there is no clear statement challenges at the EuPRAXIA collaboration is aiming to C a n a d a, a n d D a n ie l B a fi a o f Fe r m i l a b a nd young scientists. as to which is best. It will be up to the par- opening of IPAC’19. create a laser wakefield accelerator to IIT. Among other awards, the Xie Jialin T h e fi r s t s c h o ol s i n 2001 a n d 2003 t ok ticle-physics community to decide which drive a free-electron laser facility for Prize went to Vittorio Vaccaro of the Uni- place in Brazil and Mexico, two coun- capability is needed to reach the most u s e r s i n t h e n e x t fe w y e a r s. T h e s c ie nt i fic versity of Naples, the Nishikawa Tetsuji tries in Latin America that already had interesting physics. Reports on mature pr o g r a m m e w a s b o o k e n d e d b y l o c a l A u s- Prize was won by Vladimir Shiltsev of substantial involvement in experimen- hadron facilities such as Japan’s J-PARC tralian-grown talent. Suzie Sheehy from Fermilab, the Hogil Kim Prize went to tal HEP, followed by Argentina in 2005. and the LHC were balanced by the photon the University of Melbourne described Xueqing Yan of Peking University, and María Teresa Dova of the Universidad sources and electron accelerators that are the successes of particle accelerators the Mark Oliphant Prize was taken by Nacional de La Plata (UNLP) recalled becoming an increasingly robust presence and some of the future challenges, while Stanford PhD student James MacArthur. that this first Argentinian school was at IPAC, and which comprised a fifth of Henry Chapman, a director of the Center IPAC takes place annually and alter- a “strong catalyst” for Latin-American Tree level A discussion session at the 10th CLASHEP school taking place out in the open. contributions in 2019. Presentations on the for Free-Electron Laser Science at DESY nates between Asia, Europe and the groups joining the LHC experimental most recently commissioned accelerators and the , gave the Americas. Next year it will move to Caen programme. In due course, both UNLP that the impact of the school had been Gabriela González (spokesperson of LIGO were a particular highlight, with Japan’s closing plenary on how particle acceler- in France, and then to Brazil in 2021. and the Universidad de Buenos Aires for- “impressive and far beyond [his] expec- when gravitational waves were discov- SuperKEKB collider, Korea’s PAL-XFEL a t or s h a v e e n a bl e d g r o u n d br e a k i n g w or k mally joined ATLAS with support from tations”. Similarly, discussions connected ered in 2016) and Juan Martín Maldacena free-electron laser and Sweden’s MAX in coherent X-ray science. Mark Boland University of Melbourne. the national funding agencies ANPCyT with the eighth school in Ecuador in 2015 (winner of the 2012 Breakthrough Prize and CONICET. were very important in stimulating inter- in Fundamental Physics). In addition to CERN SuPerConduCtIvIty workShoP achievements of FuSuMaTech Phase-1, The fourth school in Chile in 2007 est in HEP within the universities and 50 hours reserved for plenary lectures, FuSuMaTech n o t e d pr oj e c t c o ord i n a t or A nt oi n e D a e l. gave unprecedented visibility for CERN government agencies. This advanced the parallel group discussions were held These projects include new designs for and the LHC in a country which, until plans for the Escuela Politécnica Nacional for 90 minutes most afternoons. CERN initiative levels up MRI gradient coils, the design of 14 and then, had no experimental HEP activity. and the Universidad San Francisco de Director-General took 16 T MRI magnets, and a conceptual Claudio Dib, the local director of the Quito (USFQ) to join the CMS collabora- part in a lively Q&A session by video link. O n 1 A pr i l m or e t h a n 90 d e l e g a t e s g a t h- design for new mammography magnets. school, remarked that this was a key tion, supported by the national funding The school also received visits from e re d at CER N to d i s c uss p e r s p e c t ive s on New developments are also included in event in reaching agreements for the agency, Senescyt. USFQ’s rector Carlos senior representatives of the Universi- superconducting magnet technology. the proposals, with the design for a hybrid inclusion of Chile in the ATLAS experi- Montúfar Freile described the school as dad Nacional de Córdoba (UNC), includ- The workshop marked the completion low–high temperature superconductor ment, and CERN and ATLAS represent- a milestone for physics in Ecuador. In ing Gustavo Monti, who is president of of phase 1 of the Future Superconduct- magnet, an e-infrastructure to collect atives who were present were personally 2017 the school returned to Mexico for the Argentinean Physical Society, and ing Magnet Technology (FuSuMaTech) material properties and a pulsed-heat- introduced to the authorities of the a second time, with strong interest and Francisco Tamarit, a director of the Initiative, launched in October 2017. pipe cooling system. universities and the national funding encouragement from the national fund- national research council CONICET. FuSuMaTech is a Horizon 2020 Future ators is certain, and cooperation will Phase transition In phase 2 of FuSuMaTech, launched agency, Conicyt. Following the fifth ing agency, CONACyT. Building on the tradition of the last E m e r g i n g Te c h n ol o g ie s pr oj e c t c o -f u n d e d be essential,” said Han Dols of CERN’s Han Dols (left) and with the signing of a declaration of inten- event in Colombia, in 2009, where there few schools in the series, outreach activ- by the European Commission, with the knowledge transfer group. “The work- Antoine Dael look tion between the FuSuMaTech partners on were also constructive meetings with the Diversity ities were organised at UNC in the city of s up p or t o f i n d u s t r i a l p a r t n e r s A S G, O x ford shop helps reiterate common areas of to the future. A pr i l 1, t h e 10 pr oj e c t pr o p o s a l s pr e p a r e d national funding agency and universi- The 75 students attending this year’s Cordoba. María Teresa Dova from UNLP, Instruments, TESLA, SIGMAPHI, ELLYT interest between academia and industry, during phase 1 will evolve into independ- ties, the school returned to Brazil for a There has been school were of 17 different nationali- again the local director of the school, Energy and BILFINGER, and academia and how they might benefit from each e nt pr oj e c t s a n d m a k e u s e o f o t h e r E u r o - second time in 2011. a d r a m at ic ties and more than 30% were women. explained experimental particle physics partners CERN, CEA, STFC, KIT, PSI and other’s know-how. And just as impor- pean Union programmes. “We were really The Pontificia Universidad Católica increase in the Most came from universities in Latin to a general audience, and Juan Martín CNRS. It aims to strengthen the field of tantly,” continued Dols, “FuSuMaTech impressed with the interest we got from del Perú celebrated the seventh school involvement America, while 15 were from European Maldacena, who was awarded an honor- superconductivity for projects such as the is seeking to demonstrate the benefits organisations outside of the project,” said in Peru in 2013 with a special supplement of L at i n- institutes. Lectures on HEP theory and ary doctorate, talked about black holes High-Luminosity LHC and Future Circular of this investment by setting up demon- Dael. “We currently have six industrial of the university magazine dedicated to experiment were given by leading sci- and the structure of space–time. American Collider, while demonstrating the benefits strator projects.” partners, two more have already contacted the work of local school director Alberto entists from both sides of the Atlantic, The next CLASHEP is set to take place of this investment to society at large. The successful preparation of 10 pro- us today, and we expect others.” Gago’s group, which participates in the g r oups i n with special lectures on gravitational in 2021. “The need to develop higher per- ject proposals for both R&D actions and ALICE experiment and in neutrino exper- experimental waves and cosmological collider phys- forming magnets for future acceler- industrial applications is one of the main Daniela Antonio CERN. iments at Fermilab. Gago commented HEP ics by prominent Argentinian physicists Nick Ellis and Martijn Mulders CERN.

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FIELD NOTES FIELD NOTES

new physics in he av y-ion collisions 2018. The meet i ng w as i nspi red by se v- is currently a hot topic in the search for LArge hAdron coLLider physics conference eral recent proposals to ta ke adv antage p h y s i c s b e y o n d t h e St a n d a r d M o d e l t h a t h a s Heavy ions and of the unique environment of heavy-ion g a i n e d i n c r e a s i n g i nt e r e s t i n t h e h e a v y-i o n collisions at the LHC to search for new c o m m u n it y. T h e p u r p o s e o f t h i s w or k s h o p Mexico hosts dynamic LHCP week phenomena. A key topic w as t he e x plo- was to spark ideas and initiate exchanges

hidden sectors BUAP r a t io n o f “h id d e n” or “d a r k” s e c t or s t h a t between theorists, experimentalists and The seventh edition of the Large Had- p7) published by the LHCb Collaboration T h e fi r s t d e d i c a t e d w or k s h o p o n s e a r ches c o upl e o n l y fe e bl y t o ord i n a r y m a t t e r a n d accelerator physicists. ron Collider Physics (LHCP) conference in March was presented. “Long awaited, for new physics in heav y-ion collisions could explain the dark-matter puzzle, D i s c u s s io n s a t t h e w or k s h o p fi r s t fo c u s e d took place in Puebla, Mexico, from 20 to finally observed!” was the statement took place at the Université Catholique neutrino masses or the matter–anti- on particle production mechanisms unique 25 May, hosted by the Benemérita Uni- from LHCb-spokesperson Giovanni de Louvain, Belgium, on 4–5 December m a t t e r a s y m m e t r y o f t h e u n i v e r s e. T h i s t o h e a v y-i o n c ol l i s i o n s. Si m o n K n a p e n f r o m versidad Autónoma de Puebla (BUAP). Passaleva. This result, which shows the the IAS at Princeton University and Oliver With almost 400 participants, the week different decay rates of charm quarks and G o u l d o f t h e Un i v e r s it y o f He l s i n k i e m p h a- involved dynamic discussions between charm anti-quarks, opens up new ave- sised the strongly enhanced production experimentalists and theorists on an nues of investigation for testing the SM. cross-sect ions for a x ion-l i ke par t icles and assortment of topics related to LHC The final two days of the conference PT2026 NMR Precision Teslameter magnetic monopoles in ultra-peripheral research. These ranged from heavy- featured open discussions on recent pro- heavy-ion collisions compared to proton– ion physics to precision measurements gress in the upgrades of the LHC and the proton collisions. This enhancement is due to of the Standard Model (SM), including detectors for the HL-LHC, and on vari- Reach new heights the collective action of up to 82 charges (for Higgs-sector constraints and searches ous proposals and design challenges for lead ions), thereby generating the strong- for hints of physics beyond the SM such as future colliders. The HL-LHC will be a est e le c t rom ag ne t ic fie ld s e ver pro duce d i n supersymmetry and model-independent very challenging environment in which in magnetic eld the laboratory, as the heavy ions pass each high-mass resonance searches. to distinguish particles of interest, as the other at ultra-relativistic energies. David Results from the wealth of LHC data average number of proton–proton col- d’Enterria of CERN discussed the exper- collected at 13 TeV during Run 2 (from lisions will increase from around 50 to measurement imental potential to exploit such unique 2015–2018) are beginning to be published. about 200 each time the bunches in the opportunities in searches for new phys- The ATLAS and CMS collaborations LHC beams cross. For future colliders, The Metrolab PT2026 sets a new ics by using the LHC as a “photon–photon presented new results in the search for circular and linear, delegates agreed that collider”. In contrast to these studies of supersymmetry, setting new limits on Mexican standoff the neutrinos from the decays. the community must better communi- standard for precision magnetometers. ultra-peripheral collisions, Glennys Farrar supersymmetric parameters. The latest LHCP delegates Studies involving unusual signatures cate the motivations and goals for such Leveraging 30 years of expertise building of New York University motivated interest CMS search for top squarks in events with gather to were popular at the Mexico conference. future machines with governments and the world’s gold standard magnetometers, in head-on collisions: thermal production two tau in the final state excludes interrogate the Disappearing tracks, emerging jets, dis- the public. in the quark–gluon plasma could be used to top-squark masses above 1 TeV for nearly Standard Model. placed vertices and out-of-time decays, The next edition of the conference it takes magnetic  eld measurement to search for non-conventional dark-matter massless . The first ATLAS which would each be indications of new will take place in Paris in 2020. Though new heights: measuring higher elds with candidates suc h as “se xaquarks”. Run 2 measurement for the production of processes or particles being present in the also taking place during the current long Ja n H aj e r o f t h e Un i v e r s it é C a t h ol iq u e d e tau sleptons was also presented, exclud- event, were all discussed. These signa- shutdown, many new results with the full better resolution. L o u v a i n s t r e s s e d t h a t n o t o n l y t h e pr o d u c- ing masses between 120 and 390 GeV for a tures also provide a challenge for detector LHC Run-2 statistics will be presented, as t i o n m e c h a n i s m s b ut a l s o t h e b a c k g r o u n d s massless . Both of these chal- and algorithm designs, especially at the well as progress on preparing the detec- The PT2026 offers unprecedented  exibility are qualitatively different in heavy-ion lenging analyses contain a high amount high-luminosity LHC (HL-LHC). tors and the accelerator for Run 3. collisions. This can, for example, allow of missing momentum, originating from The recent observation of CP violation in the choice of parameters, interfacing s e a r c h e s for l o n g-l i v e d p a r t i c l e s i n p a r a m- the lightest supersymmetric particle and in charm quarks (CERN Courier May/June Clara Nellist University of Göttingen. and probe placement, as well as greatly eter regions that are hard to probe in proton collisions due to limitations related to the A dditive mAnufActuring workshop improved tolerance of inhomogeneous LAL high pile-up during future LHC runs. Tricky component? properties, mechanical strength, elds. And with Ethernet & USB interfaces A key question that emerged from the electrical conductivity, new alloys and LabVIEW software, it  ts perfectly into workshop was how to optimise the choice Use 3D printing... and post-processing, the technique is modern laboratory environments. of ions and the beam parameters for beginning to be used for working accel- new-physics searches without compromis- erator components. Participants of the ing the study of the quark–gluon plasma. Some 120 physicists gathered in Orsay Orsay event heard about the beam test www.agence-arca.com - Photo: Scott Maxwell, Master le - Photo: Scott Maxwell, Master www.agence-arca.com The discussion was extremely helpful for on 13–14 December 2018 for a workshop at an accelerator (LAL’s photoinjector elucidating the hard engineering restric- on additive manufacturing – popularly PHIL), of a beam position monitor and tions within which any novel proposals called 3D printing – with metals. The about the performances of RF anten- must fit, suc h as t he capac it y of t he i njec- goal was to review the work being done nas designed at Université de Rennes tors and t he beam li fet ime. in Europe (particularly at CERN, CEA and for future space missions. Plans for The workshop was very successful and CNRS) on the application of the technique employing additive manufacturing at triggered many discussions, including the to high-energy physics and astrophysics. future accelerators and HEP experiments proposal to submit an input for the update 3D printing makes possible novel were also discussed. of the European Strategy for Particle Physics and optimised designs that would be Although metal additive manufactur- and for a follow-up event in 2020. The topic difficult to create with conventional ing is currently limited to a few applica- is still young, and we are very much looking methods. Embedded radio-frequency t i o n s, t h e w or k s h o p, w h i c h w a s t h e fi r s t for w a rd t o i n p ut f r o m t h e w id e r c o m mu n it y. (RF) cavities such as those featured in of its kind, showed that there is strong Pantone 286 Pantone 032 spiral-shaped cooling channels are one the removal of material in one part of 3D printing potential for it to play a larger role in the Further reading example. Another comes from detector the mesh may destroy another part of Physicists met up coming years. R Bruce et al. 2019 arX iv:1812.07688. design: mesh structures, as required it; but they are easy to build with in Orsay for the for many gas-filled ionisation tracking additive manufacturing. additive Nicolas Delerue Laboratoire de Magnetic precision has a name www.metrolab.com Marco Drewes Université Catholique detectors, are often difficult to man- Despite the remaining challenges, manufacturing l’Accélérateur Linéaire, CNRS/IN2P3 and de Louvain. ufacture with traditional methods as which relate to ultra-high-vacuum workshop. Université Paris-Sud.

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TRIBUTE MURRAY GELL-MANN 1929–2019

A solution for the current measurement challenges GELL-MANN’S MULTI- DIMENSIONAL GENIUS WEF/M Wuertenberg LIBERA CURRENT METER Murray Gell-Mann was one of the great geniuses of the 20th century, - 4 current input channels with BNC connectors says Lars Brink, and stands out - 2.5MHz, 18-bit A/D conversion - 6 controllable current ranges from 60nA to 2mA among other Nobel laureates. - better than 10pA rms current resolution - web-server and web-based GUI included ne of the 20th century’s most amazing brains has - easy calibration of each channel and range stopped working. Nobel laureate Murray Gell-Mann - ideal readout for wire-scanners, Faraday cups O died on 24 May at the age of 89. It is impossible to and ion. chambers write a complete obituary of him, since he had so many dimensions that some will always be forgotten or neglected. Scan for more information Murray was the leading particle theorist in the 1950s a n d 1960 s i n a fie ld t h at h a d at t r a c t e d t h e br i g ht e s t yo ung Instrumentation Technologies, d.o.o. / Velika pot 22, SI-5250 Solkan, Slovenia / e: [email protected] / w: www.i-tech.si stars of the post-war generation. But he was also a polyglot Cryogenic WafPro#1-CERN 9/21/13 3:06 PM Page 1 who could tell you any noun in at least 25 languages, a walking encyclopaedia, a nature lover and a protector of e n d a n g e r e d s p e c ie s, w h o k n e w a l l t h e flo w e r s a n d bi rd s. He was an early environmentalist, but he was so much more. HIGH VOLTAGE It has been one of the biggest privileges in my life to have worked with him and to have been a close friend of his. Murray Gell-Mann was born into a Jewish immigrant AMPLIFIERS family in New York six weeks before the stock-market crash Cryogenic Wafer of October 1929. He was a trailing child, with a brother Probe Stations who was nine years older and relatively aged parents. He Employing unique and proprietary circuitry to used to joke that he had been born by accident. His father produce a closed-loop amplifier system which had failed his studies and, after Murray’s birth, worked features exceptional DC stability and wideband as a guard in a bank vault. Murray was never particularly performance for driving capacitive loads. close to father, but often talked about him A giant of theoretical physics Murray Gell-Mann photographed at the annual • VVoltage Range to ±50 kV Child prodigy meeting of the World Economic Forum in 2012. According to family legend, the first words that Murray • SSlew Rates to 1500 V / µs spoke were “The lights of Babylon”, when he was looking The late Myron Bander had learnt and studied an incom- • CCurrent to 10 A at the night sky over New York at the age of two. At three, prehensible word and steered the discussion on to it over he could read and multiply large numbers in his head. At lu n c h. O f c o u r s e M u r r a y k n e w w h at t h e w ord w a s. He e v e n Applications include nano science, materials and • BBandwidth to 3 MHz spintronics fi v e h e c o u ld c or r e c t old e r p e o ple a b o ut t h e i r l a n g u a geand recalled the previous and subsequent entries on the page. in discussions. His interest for numismatics had already Murray’s parents didn’t know what to do with him, but 3.2 K - 675 K; high vacuum or UHV begun: when a friend of the family showed him what he his piano teacher (music was not his strong side) made Up to 8 probes, DC to 67 GHz, plus fiber optics +1-716-438-7555 Trek is now home to claimed was a coin from Emperor Tiberius’ time, Murray them apply for a scholarship so that he could start at a Zoom optics with camera and monitor Monroe Electronics corrected the pronunciation and said it was not from that good private school. He was three years younger than [email protected] Cooling options: liquid helium, liquid nitrogen or Electrostatic & ESD time. At the age of seven, he participated in – and won – a his classmates, yet they always looked to him to see if he cryogen free www.trekinc.com product line. major annual spelling competition in New York for students a p pr o v e d o f w h at t h e t e a c h e r s s a id. H i s t e s t s w e r e f a u lt le s s, Horizontal, vertical or vector magnetic field options up to the age of 12. The last word that only he could spell except for the odd exception. Once he came home and had are available and explain was “subpoena”, also citing its Latin origins scored “only” 97%, to which his father said: How could THE AUTHOR and correcting the pronunciation of the moderator. you miss this? His brother, who was more “normal”, was Contact us today: Lars Brink [email protected] By the age of nine he had essentially memorised the a great nature lover and became a nature photographer Chalmers Institute www.janis.com/ProbeStations.aspx Encyclopaedia Britannica. The task sounds impossible, but and later a journalist. He taught Murray about birds and of Technology, www.facebook.com /JanisResearch some of us did a test behind his back once in the 1970s. plants, which would become a lifelong passion. Sweden.

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TRIBUTE MURRAY GELL-MANN 1929–2019 TRIBUTE MURRAY GELL-MANN 1929–2019 ortsyo eS taF nti ute it Inst Fe a nt Sa he t of y tes Cour Cour tes y of t he Sa nt a Fe Inst it ute ute it Inst Fe a nt Sa he t of y tes Cour time Petermann and Stückelberg had published this result. Finnegans Wake, “three quarks for Muster Mark”. The same This was during the aftermath of QED and Gell-Mann idea was also put forward by George Zweig who called them wanted to attack the strong interactions. He started his “aces”. It was a very difficult thing for Murray to propose odyssey to classify all the new particles and introduced such a wild idea, and he formulated it extremely carefully the concept of “strangeness” to specify the and the t o le a v e a l l d o or s o p e n. A g a i n, h i s f at h e r’s a p pr o v a l lo o m e d c or r e s p o n d i n g b a r yo n s. T h i s w a s a l s o d o n e i n d e p e n d e nt l y in the background. Cour tes y of t he Sa nt a Fe Inst it ute by Kazuhiko Nishijima. When he was back at the IAS in With the introduction of current algebra he had laid

1955, Murray solved the problem with KL and K s, the two the ground for the explosion in particle theory during the decay modes of the neutral kaons in modern language 1970s. I n 1966, We i s s k o p f’s 60 t h bi r t h d a y w a s c e le br at e d, (better known as the τ–θ puzzle). According to him, he and somehow Murray failed to show up. When he later showed this to Abraham Pais who said, “Why don’t we received the proceedings, he was so ashamed that he did p u bl i s h it?”, w h ic h t h e y d id. T h e y w e r e n e v e r f r ie n d s a f t e r not open it. Had he done so, he would have found Nam- that. Murray also once told me that this was the hardest bu’s suggestion of a non-abelian gauge field theory with problem that he had solved. coloured quarks for the strong interactions. Nambu did not l i k e f r a c t io n a l c h a r g e s s o h e h a d g i v e n t h e q u a r k s i nt e g e r A cavalcade of results charges. Murray later said that, had he read this paper, A g e d 26, h e le c t u r e d at C a lt e c h o n h i s r e n or m a l i s at io n a n d he would have been able to formulate QCD rather quickly. d e v e lo p t h e t h e or y. Ev e nt u a l l y, I c o u ld n’t g o t o t h e US q u it e Cultivated k a o n wor k. R ic h a rd Fe y n m a n, w h o w a s t h e g r e at e s t p h y s- as often. Murray had also lost his wife in the early 1980s Gell-Mann in his icist at the time, said that he thought he knew everything, Legacy and never really recovered from this. In the mid-1980s he office at the Santa but these things he did not know. Feynman immediately When, at the age of 40 in 1969, he received the g o t t h e c h a n c e t o s e t up a n e w i n s t it ut e i n S a nt a Fe, w h ic h Fe Institute. s a id t h at M u r r a y h a d t o c o m e t o C a lt e c h a n d d r a g g e d h i m t o in Physics as the sole recipient, he had been a heavily nom- became completely interdisciplinary. He loved nature in the dean. A few weeks later, he was a full professor. A large inated candidate for the previous decade. Next year the New Me x ico and here he could work on t he issues t hat he cavalcade of new results began to come out. Because he had Nobel archives for this period will be open, and scholars now preferred, such as linguistics and large-scale order difficulty relinquishing his works, they numbered just a can study the material leading up to the prize. Unfortu- in nature. He dropped particle physics but was always few a year. But they were like cathedrals, with so many new nately, his father had died a few weeks before the prize interested in what happened in the field. d e t a i l s t h at h e c a m e t o d o m i n at e m o d e r n p a r t ic le p h y s ic s. announcement. Murray once said to me, “If my father had h a d t a k e n o v e r t h e le a d e r s h i p o f f u n d a m e nt a l p h y s ic s a n d After the ground-breaking work of T D Lee and C N Yang l i v e d t wo w e e k s lo n g e r, m y l i fe wo u ld h a v e b e e n d i ffe r e nt.” Murray could not compete there. Cour tes y of t he A rc h ives, Ca l i for n ia Inst it ute of Tec h nolog y on violation in the weak interactions, Gell-Mann During the 1950s and 1960s Gell-Mann had often been B e i n g c o n s id e r e d t h e w orld’s m o s t i nt e l l i g e nt p e r s o n d id started to work on a dynamical theory – as did Feynman. d e s c r i b e d i n t h e pr e s s a s t h e w orld’s m o s t i nt e l l i g e nt m a n. not make Murray very happy. He had trouble finding real In the end the dean of the faculty forced them to publish With a Nobel Prize in his pocket, the attraction to sit on friends among his peers. They were simply afraid of him. toget her, a nd t he V–A t heor y w as bor n. G eorge Suda rsha n various boards and committees became too strong to resist. I often saw people looking away. The post-war research and Robert Marshak also published the same result, and His commitment to conserving endangered species also world is a single great world championship. For us who t h e r e w a s a lo n g-l a s t i n g fi g ht a b o ut w h o h a d t old w h o b e fore. took up more of his time. Murray had also become a great were younger, it was so obvious that he was intellectually M u r r a y’s p a r t o f t h e p a p e r, w h ic h i s t h e s e c o n d h a l f, i s a l s o c ol le c t or o f pr e- C olu m bi a n a r t e f a c t s a n d t h e s e w e r e o f t e n s up e r ior t o u s t h at w e w e r e n o t d i s t u r b e d b y it. A l l t h e t i m e, Passion for A t t h e a g e o f 15, h e fi n i s h e d h i g h s c h o ol a n d w e nt t o Ya le. a fi r st ske tc h of t he St a nd a rd Mo de l, a nd e ver y se nte nce i s expensive and difficult to obtain. though, the shadow of his father was sitting on his shoulder, knowledge He d id n o t k n o w w h ic h s u bj e c t h e w o u ld c h o o s e a s a m aj or, worth reading carefully. It takes students of exegetics to I n t h e 1970 s, h e w a s d i s pl a c e d f r o m t h e t h r o n e b y p e o ple w h ic h le d h i m t o o o f t e n t o s h o w off w h e n h e d id n o t n e e dto. Gell-Mann as a boy, since he was interested in so many subjects. It became u n v e i l a l l t h e g lor y o f M u r r a y’s t e x t s. M u r r a y w a s t o p h y s ic s from the next generation. Murray was still the one invited Sometimes people are born with all the neurons in the a young man and a physics, partly to please his father who had insisted on w rit ing what Joseph Conrad w as to novel w rit ing! to give the closing lectures at major conferences, but his right place. We sometimes hear about the telephone- Caltech professor. e n g i n e e r i n g s uc h t h at h e c o u ld g e t a g o o d j o b. He t h e n w e nt Murray then turned back to the strong interactions o w n r e s e a rc h s t a r t e d t o s u ffe r s o m e w h at. I n t h e m id-1970 s, director y geniuses or people who k now railw ay sc hedules to MIT for his doctoral studies, receiving the legendary and, with Maurice Lévy, developed the non-linear sigma I came to Caltech as a young postdoctoral fellow. I had met by heart, but who otherwise are intellectually normal, if V ic t or “V i k i” We i s s k o p f a s h i s a d v i s or. M u r r a y w a nt e d t o d o model for pion physics to formulate the partially con- h i m i n a g r o up b e for e, b ut t r e m ble d l i k e a n a s p e n le a f w h e n not r at her wea k. The f ac t t hat a fe w of t hem e ver y cent ur y s o m e t h i n g pio n e e r i n g, b ut h e d id n’t s uc c e e d. He t r ie d for a served axial vector current (PCAC). This was published I first met him there. He had, of course, found out from also get the neurons to make them intellectually superior is w h ole s e m e s t e r a n d at t h e s a m e t i m e s t ud ie d C h i n e s e a n d within days of ’s ground-breaking paper where in Sweden I came and pronounced my name just amazing. Among all Nobel laureates in physics, Murray Gell- learnt enough characters to read texts. He finally decided where he understood pion physics and PCAC in terms of right, and demanded that everyone else in the group do M a n n s t a n d s o ut. O t h e r s h a v e p e r h a p s d o n e ju s t a s muc h i n to present a in , which was approved spontaneous breaking of the chiral symmetry. In a note so. Pierre Ramond also arrived as a postdoc at that time, their research in physics and may be remembered longer, but that he never wanted to talk about. When Weisskopf, added to the proof they introduced a “funny” angle to hav i ng been conv i nced by Mur r ay to leave h is posit ion at but I do not think that anyone had such a breadth in their later in life, was asked what his biggest contribution to describe the decay of 14O, which a few years later became Yale. After a few months we started to work together on k n o wle d g e. Jo h n v o n Ne u m a n n, t h e Hu n g a r i a n–A m e r ic a n physics w as, he answered: “Murray Gell-Mann”. t h e C a bi b b o a n g le i n Nic ol a C a bi b b o’s u n i v e r s a l t r e at m e nt . We did the long calculations, since Murray mathematician who, among other things, was the first to At the age of 21 Murray was ready to fly and went to of t he wea k interact ions. w a s o f t e n a w a y. B ut h e a l w a y s c o nt r i b ut e d a n d c o u ld s p o t construct a computer was another such universal genius. the Institute for Advanced Study (IAS) as one of Robert Gell-Mann then made the great breakthrough when he any weak links in our work immediately. Once, when we He c o u ld s h o w off k n o w i n g G o e t h e b y h e a r t a n d o n h i s death Oppenheimer’s young geniuses. In the next year he went classified the strongly interacting particles in terms of were in the middle of solving a problem after a period of bed he cited the first sentence on each page ofFaust for his t o t h e Un i v e r s it y o f C h ic a g o u n d e r E n r ic o Fe r m i, fi r s t a s a n f a m i l ie s o f SU(3), a d i s c o v e r y a l s o m a d e b y Yu v a l Ne’e m a n. several days, he came in and looked at what we did and br o t h e r. M u r r a y w a s c e r t a i n l y a p a i n for A m e r ic a n l i n g u i s t s, Gell-Mann instructor and in a few years became an associate professor. The paper was never published in a journal and he used to w r o t e t h e a n s w e r o n t h e b o a rd. T wo d a y s l at e r w e c a m e t o as he could say so many words in so many languages that was often Even though he had not yet produced outstanding work, joke that one day he would find out who rejected it. With exactly that result. John Schwarz, who was a world cham- he could always gain control over a discussion. Sometimes w h e n h e c a m e t o C h ic a g o h e w a s br a n d e d a s a g e n iu s. A t t h e this scheme he could predict the existence of the triply pion in suc h calculat ions, w as impressed and humbled. T h e r e a r e s o m a n y m or e s t or ie s t h at I c o u ld t e l l. O n c e h e described there are I A S he had sta r ted to work on pa r t ic le physics. He col lab- strange Ω– baryon, which was discovered in 1964 right W h e n I le f t C a lt e c h I g o t a c a r t e bl a n c h e f r o m M u r r a y t o t old m e “Ju s t t h i n k w h at I c o u ld h a v e d o n e i f I h a d wor k e d in the press people born orated with Francis Low on renormalisation and realised where he predicted it would be. It paved the way for Gell- return as often as I wanted, during which I worked with more with physics.” His almost crazy interest in so many as the with all the that the coupling constant in a renormalisable quantum Mann’s suggestion in 1963 that all the baryons were made Schwarz and Michael Green developing . Mur- areas took a lot of time away from physics. But he will world’s most neurons in the field theory runs with energy. As would happen so often, up o f t h r e e f u n d a m e nt a l p a r t ic le s, w h ic h i n t h e p u bl i s h e d ray was always very positive about our work, which few still be remembered, I hope, as one of the great geniuses intelligent right place he procrastinated with the publication until 1954, by which form he came to call quarks, after a line in James Joyce’s others were. It was entirely thanks to him that we could of t he 20t h centur y.  man

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TRIBUTE MURRAY GELL-MANN 1929–2019 TRIBUTE MURRAY GELL-MANN 1929–2019 CERN-262-3-79 Physics Particle Modern M from ThomsonAdapted

⊗ ⊗ = ⊕ ⊗ (Cambridge, 2013) (Cambridge,

STRONG INTERACTIONS

Harald Fritzsch, who collaborated with Gell-Mann in the early 1970s, describes the ⊗ = = ⊕ steps that led to a full understanding of strong interactions. Fig. 1. qqq multiplets in SU(3) symmetry broken down into the 6 ⊗ 3 part (second row), Courtesy of the Archives, California Institute of Technology of Institute California Archives, the of Courtesy urray Gell-Mann’s scientific career began at yielding a totally symmetric baryon decuplet and a mixed-symmetry baryon octet. the age of 15, when he received a scholarship The remaining 3 ⊗ -3part (not shown) yields a mixed-symmetry octet and a totally M from Yale University that allowed him to study antisymmetric singlet state. physics. Afterwards he went to the Massachusetts Institute of Technology and worked under Victor Weisskopf. He Moo-Young Han and Yoichiro Nambu, that quarks possess completed his PhD in 1951, at the age of 21, and became a additional properties that keep the Pauli principle intact. postdoc at the Institute for Advanced Study in Princeton. By imagining the quarks in three “colours” – which later The following year, Gell-Mann joined the research group came to be called red, green and blue – hadrons could of Enrico Fermi at the University of Chicago. He was par- be considered as colour singlets, the simplest being the ticularly interested in the new particles that had been bound states of a quark and an antiquark (meson) or of discovered in cosmic rays, such as the six and the three quarks (baryon). Since baryon wave functions are four K-mesons. Nobody understood why these particles Commanding figureGell-Mann lecturing on grand unification antisymmetric in the colour index, there is no problem with were created easily in collisions of nucleons, yet decayed in CERN’s theory conference room in 1979. the Pauli principle. Taking the colour quantum number as rather slowly. To understand the peculiar properties of the a gauge quantum number, like the electric charge in QED, new hadrons, Gell-Mann introduced a quantum number, that there exist four Δ resonances, three Σ resonances and yields a of the strong interactions: colour which he called strangeness (S): nucleons were assigned two χ resonances. There is no SU(3)-representation with symmetry is an exact symmetry and the gauge bosons S = 0; the Λ hyperon and the three Σ hyperons were assigned nine members, but there is a decuplet representation with are massless , which transform as an octet of the S = (–1); the two Ξ hyperons had S = (–2); and the negatively 10 members. Gell-Mann predicted the existence and the colour group. Nambu and Han had essentially arrived at charged K-meson had S = (–1). mass of a negatively charged 10th particle with strangeness (QCD), but in their model the S = (–3), which he called the Ω particle. quarks carried integer electrical charges. Strange assumptions The Ω is unique in the decuplet: due to its strangeness I was introduced to Gell-Mann by Ken Wilson in 1970 at Gell-Mann assumed that the strangeness quantum number it could only decay by the , and so would the Aspen Center of Physics, and we worked together for a is conserved in the strong and electromagnetic interac- have a relatively long lifetime. This particle was discovered period. In 1972 we wrote down a model in which the quarks tions, but violated in the weak interactions. The decays of in 1964 by Nicholas Samios and his group at Brookhaven had fractional charges, proposing that, since only colour the strange particles into particles without strangeness Triply strange Yuval Ne’eman (left) and Gell-Mann in March 1964, holding a copy National Laboratory, at the mass Gell-Mann had predicted. singlets occur in the spectrum, fractionally charged quarks could only proceed via the weak interaction. of the event display that proved the existence of the Ω– baryon that was predicted by The SU(3) symmetry was very successful and in 1969 Gell- remain unobserved. The discovery in 1973 by , The idea of strangeness thus explained, in a simple way, Gell-Mann’s “”. Mann received the “for his contri- David Politzer and that the self-interaction the production and decay rates of the newly discovered butions and discoveries concerning the classification of of the gluons leads to asymptotic freedom – whereby the hadrons. A new particle with S = (–1) could be produced by of the weak interaction in terms of a universal Fermi inter- elementary particles and their interactions.” gauge coupling constant of QCD decreases if the energy is the strong interaction together with a particle with S = (+1) action given by the product of two currents and the Fermi In 1962 Gell-Mann proposed the algebra of currents, increased – showed that quarks are forever confined. It was – e.g. a negatively charged Σ can be produced together constant. These currents were both vector currents and which led to many sum rules for cross sections, such as rewarded with the 2004 Nobel Prize in Physics, although with a positively charged K meson. However, a positively axial-vector currents, and the lepton current is a product the Adler sum rule. Current algebra was the main topic a rigorous proof of quark confinement is still missing. charged Σ could not be produced together with a negatively of a charged lepton field and an antineutrino field. The of research in the following years and Gell-Mann wrote Gell-Mann did not just contribute to the physics of strong charged K meson, since both particles have S = (–1). “V–A” theory showed that since the electrons emitted in several papers with his colleague Roger Dashen on the topic. interactions. In 1979, along with Pierre Ramond and Richard In 1954 Gell-Mann and Francis Low published details of a beta-decay are left-handed, the emitted antineutrinos Slansky, he wrote a paper discussing details of the “seesaw the renormalisation of (QED). are right-handed – thus parity is not a conserved quantum Quark days mechanism” – a theoretical proposal to account for the very They had introduced a new method called the renormal- number. Some experiments were in disagreement with the In 1964 Gell-Mann discussed the triplets of SU(3), which small values of the neutrino masses introduced a couple isation group, which Kenneth Wilson (a former student of new theory. Feynman and Gell-Mann suggested in their he called “quarks”. He proposed that quarks were the con- of years earlier. After 1980 he also became interested in Gell-Mann) later used to describe the phase transitions in paper that these experiments were wrong, and it turned stituents of baryons and mesons, with fractional elec- string theory. His wide-ranging interests in languages, condensed-matter physics. Specifically, Gell-Mann and out that this was the case. tric charges, and published his results in Physics Letters. and other areas beyond physics are also well documented. Low calculated the energy dependence of the renormalised In 1960 Gell-Mann invented a new symmetry to describe Feynman’s former PhD student George Zweig, who was I enjoyed working with Murray Gell-Mann. We had sim- c o upl i n g c o n s t a nt. I n QE D t h e e ffe c t i v e c o upl i n g c o n s t a nt the new baryons and mesons found in cosmic rays and working at CERN, independently made the same proposal. ilar interests in physics, and we worked together until 1976 increases with the energy. This was measured at the LEP in various accelerator experiments. He used the unitary But the quark model was not considered seriously by many when I left Caltech and went to CERN. He visited often. In collider at CERN, and found to agree with the theoretical The quark group SU(3), which is an extension of the isospin symmetry physicists. For example, the Ω is a of three May 2019, during a trip to Los Alamos Laboratory, I was model was not prediction. based on the group SU(2). The two nucleons and the six strange quarks placed symmetrically in an s-wave, which fortunate to have had the chance to visit Murray at his house THE AUTHOR considered  In 1955 Gell-Mann went to Caltech in Pasadena, on the hyperons are described by an octet representation of SU(3), violated the Pauli principle since it was not anti-symmetric. in Santa Fe one last time. Harald Fritzsch invitation of , and was quickly promoted seriously as are the eight mesons. Gell-Mann often described the In 1968, quarks were found indirectly in deep-inelastic Ludwig- to full professor – the youngest in Caltech’s history. In 1957, by many SU(3)-symmetry as the “eightfold way” in reference to the electron–proton experiments performed at SLAC. z Further memories of Gell-Mann can be found online at Maximilians- Gell-Mann started to work with Feynman on a new theory physicists eightfold path of Buddhism. At that time, it was known By then it had been proposed, by Oscar Greenberg and by cerncourier.com. Universität, .

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FEATURE CERN COURIER AT 60 WE’VE BEEN HERE BEFORE…

Tales of colliders contained in 60 illustrious years of CERN Courier offer a r ic h perspective on the strategic dec isions f ac i ng t he field to day.

n April 1960, Prince Philip, husband of Queen Eliz- abeth II, piloted his Heron airplane to Geneva for an I i n for m a l v i s it t o C E R N. Ha v i n g t o u r e d t h e l a b or at or y’s br a nd ne w “25 GeV” Proton Synchrotron (PS), he turned to his host, president of the CERN Council François de Ro s e, a n d s t r uc k at t h e h e a r t o f f u n d a m e nt a l e x plor at io n: “W hat have you got i n m i nd for t he f ut ure? Hav i ng bui lt this machine, what next?” he asked. De Rose replied that this was a big problem for the field: “We do not really k n o w w h e t h e r w e a r e g oi n g t o d i s c o v e r a n y t h i n g n e w b y going beyond 25 GeV,” he said. Un b e k n o w n t o d e R o s e a n d everyone else at that time, the weak gauge bosons and other phenomena that would transform particle physics were ly ing not too far above t he energ y of t he PS. This is a story repeated in physics, and which CERN Courier, celebrating its 60th anniversary this summer, offers a bite-sized glimpse of. Lost humour Top left: in April 1984 Phil Bryant highlighted the closure of the ISR with the intended message: The first issue of theCourier was published in August “Gentlemen, this is definitely the last project before we close the ISR!”. Top right: this cartoon from the August 1959, just a few months before the PS switched on, at 1969 issue was titled “Where we stand – 1969” and illustrated the troublesome time that theory was having in a time when accelerators were taking off. The PS was trying to accommodate the discovery of the splitting of the A2 meson. Bottom left: the November 1976 issue the first major European machine, quickly reaching an carried this cartoon by Bob Gould of SLAC, depicting the reaction of the “man in the street” at a time when e ne r g y of 28 G eV, on ly t o b e s u r p a s s e d t he fol lo w i n g ye a r high-energy physicists were in a state of euphoria over the discovery of the J/ψ, captioned: “Salutary reminder to by Brookhaven’s Alternating Gradient Synchrotron. The all who attempt to popularise science”. Bottom right: the October 1979 issue carried Alvaro De Rûjula’s view of the March 1960 issue of the Courier described a meeting at current scene in particle theory: “Who will succeed in rescuing the quark damsel confined in her tower?” C E R N w h e r e 2 45 s c ie nt i s t s f r o m 2 8 c o u nt r ie s h a d d i s c u s s e d “a doz en m ac h i nes now b e i ng desig ne d or con st r uc te d”. CERN’s 12Member States”. history that most physics students learn. with a minimum growth for total European science. He Even plasma-based accelerat ion tec hniques – including The general situation of elementary particle physics Within a few years of PS operations, attention soon w r o t e b old l y: “T h e s c ie nt i fic c a s e for E u r o p e’s c o nt i nu i ng a “plasma betatron” at CERN – were on t he table. back then, argued the August 1962 issue, could be lik- turned to a machine for the 1970s. A report on the 24th forcefully in high-energy physics is overwhelming; the ened to atomic physics in 1924 before the development session of the CERN Council in the July 1963 issue noted equipment needed is technically feasible; the scientific A time gone by of quantum mechanics. Summarising the 1962 ICHEP ECFA’s recommendation that high priority be given to the manpower needed will be available; the money is trivial. T h e pic t u r e i s n o t s o d i ffe r e nt t o d a y (se p 7), t h o u g h a d m it- conference held at CERN, which attracted an impressive construction in Europe of two projects: a pair of intersecting Only conservatism or timidity will stop it.” t e d l y t h i n n e r o n pr oj e c t s u n d e r c o n s t r uc t io n. S o m e t h i n g s 450 physicists from 158 labs in 39 countries, the leader storage rings (ISR, which would become the world’s first remain eerily pertinent: swap “25 GeV” for “13 TeV” in de of the CERN theory division Léon Van Hove wrote: “The hadron collider) and a new proton accelerator of a very high The development of science Rose’s response to Prince Philip, and his answer still stands very fact that the variety of unexpected findings is so energy “probably around 300 GeV”, which would be 10 times Similar sentiments exist now in view of a post-LHC with respect to what lies beyond the LHC’s energy. Other puzzling is a promise t hat new fundamental discoveries the size of the PS (and eventually renamed the Super Proton collider. There is also nothing new, as the field grows t h i ng s a re of a t i me gone b y. The t h i rd i ssue of t he Courier, may wel l be i n store at t he end of a long process of eluc i- Synchrotron, SPS). Mervyn Hine of the CERN directorate ever larger in scale, in attacks on high-energy physics in October 1959, proudly declared that “elementary parti- dation.” Van Hove was right, and the 1960s brought the for applied physics outlined in the August 1964 issue how from outside. In an open letter published in the Courier ...the money THE AUTHOR c les number 32” (by 1966 t hat number had g row n to more q u a r k m o d e l a n d e le c t r o w e a k t h e or y, l a y i n g a p at h t o t h e this so-called “Summit program” should be financed. in April 1964, nuclear Alvin Weinberg argued is trivial. Only Matthew than 50 – see “Not so elementary” on p32). Another early Standard Model. Not that this paradigm shift is much He estimated the total annual cost (including that of the that the field had become “remote” and that few other conservatism Chalmers issue l i kened t he 120 million Swiss Franc cost of the PS to apparent when flicking through issues of theCourier from assumed national programmes) to be about 1100 million branches of science were “waiting breathlessly” for or timidity editor. “10 cigarettes for each of the 220 million inhabitants of the period; only hindsight can produce the neat logical Swiss Francs by 1973, concluding that this was in step insights from high-energy physics without which they will stop it

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FEATURE CERN COURIER AT 60 FEATURE CERN COURIER AT 60

due to the difficulty of selecting a site and: “At the same Search for the time it is disturbing to the traditional unity of CERN that naked bottom only half the Member States (Austria, Belgium, Federal The December 1977 Republic of Germany, France, Italy and Switzerland) have issue looked back so far adopted a positive attitude towards the project.” That over an exciting half-a-century later, the SPS, soon afterwards chosen to year that saw the be built at CERN, would be feeding protons into a 27 km- discovery of the circumference hadron collider with a centre-of-mass energy upsilon particle: of 13 TeV was unthinkable. “a new type of quark most A giant LEP for mankind frequently An editorial in the January/February 1990 issue of the interpreted as Courier titled “Diary of a dramatic decade” summed up a consisting of a crucial period that had the Large Electron Positron (LEP) quark–antiquark collider at its centre: Back in 1980, it said, the US was the pair of a new type”. “mecca” of high-energy physics. “But at CERN, the vision The postulated new Not so elementary This figure, reprinted from the December 1966 issue, shows the date of , the invention of new beam ‘cooling’ tech- quark, wrote the of the discovery of what were then thought to be elementary particles. Altogether about niques by , and bold decisions under Courier, “has been 100 different particles were known, not counting their corresponding . Most the joint Director-Generalship of and Léon assigned names like of the discoveries before 1955 were made in cosmic-ray experiments, while the large Van Hove had led to preparations for a totally new research ‘beauty’ , ‘top’ or number found after 1960 were produced and investigated mainly with the proton assault – a high-energy proton– collider.” The ‘bottom’. Just as the synchrotrons at Berkeley, Brookhaven and CERN. 1983 discoveries of the had, it continued, J/ψ provoked the “nudged the centroid of particle physics towards Europe,” search for naked and, with LEP and also HERA at DESY operating, Europe charm, so the J Sharp was “casting off the final shackles of its war-torn past”. upsilon now offers

CERN 213.10.76 Despite involving what at that time was Europe’s largest physicists the civil-engineering project, LEP didn’t appear to attract much exciting prospect in public attention. It was planned to be built within a constant 1978 of looking for CERN budget, but there were doubts as to whether this was naked bottom.” possible (see p39). The September 1983 issue reported on an The issue closed ECFA statement noting that reductions in CERN’s budget had with this satirical put is research programme under “severe stress”, impair- look (left) at what ing the lab’s ability to capitalise on its successful proton– the next year antiproton programme. “The European Laboratories have might hold. demonstrated their capacity to lead the world in this field, but the downward trend of support both for CERN and in the CERN 213.8.79 Member States puts this at serious risk,” it concluded. At the same time, following a famous meeting in Lausanne, the ECFA report noted that proton–proton collision energies of the order of 20 TeV could be reached with superconducting 50th anniversary in September 2004, former Director-Gen- author lists and practical concerns about the size of the even magnets in the LEP tunnel and “recommends that this eral Luciano Maiani predicted what the post-2020 future bigger LHC-experiment collaborations over the horizon. Faces and places Top left: the “seraphic contentment” of Hildred Blewett when full possibility be investigated”. might look like, asserting that “a big circular tunnel, such Others are more strategic. energy had been achieved at the PS on 25 November 1959. Top right: a smiling November Physicists were surprisingly optimistic about the pos- as that required by a Very Large Hadron Collider, would It is remarkable to read through back issues of the Courier 1976 Sam Ting at his experiment at the ISR “where he continues the search for leptons sibility of such a large hadron collider. In the October 1981 have to go below Lake Geneva or below the Jura (or both). from the mid-1970s to find predictions for the masses of the which has dominated his research life”. Bottom left: John Ellis snapped in an article about issue, wrote: “In the next decade, one may Either option would be simply too expensive to consider. W and Z bosons that turned out to be correct to within 15%. cosmology in the July/August 1983 issue. Bottom right: the CERN Courier team featured envisage the possible installation of a pp– collider in the This is why a 3–5 TeV (CLIC) would This drove the success of the Spp–S and LEP programmes in the October 1979 issue, resplendent in CERN 25th anniversary T-shirts (left to right: LEP tunnel and the construction of a supertevatron… But be the project of choice for the CERN site.” It is the kind of and led naturally to the LHC – the collider to hunt down the Henri-Luc Felder, Monika Wilson, Brian Southworth (editor), Micheline Falciola and what will happen to the subject 25 years from now?” he decision that the current CERN management is weighing final piece of the electroweak jigsaw, the “so-called Higgs Gordon Fraser. Those were the days! ). asked. “Accelerators may become as extinct as dinosaurs up today, 15 years later. mesons” as a 1977 issue of the Courier put it. Following unless our community takes heed now and invests efforts the extraordinary episode that was the development and could not progress. Director-General Viki Weisskopf, on new designs.” Almost 40 years later, the laser-based Driving success completion of the Standard Model, we find ourselves in a writing in April 1965, concluded that the development of acceleration schemes that Salam wrote of, and others, such This collider-centric view of 60 years of CERN Courier similar position as we were in the PS days regarding what science had arrived at a critical stage: “We are facing today as muon colliders, are still being discussed. does little justice to the rest of the magazine’s coverage lies over the energy frontier. Looking back at six decades a situation where it is threatened that all this promising Accelerator physicist Lee Teng, in an eight-page long o f fi x e d-t a r g e t p h y s ic s, n e ut r i n o p h y s ic s, c o s m olo g y a nd of fundamental exploration as seen through the imperfect research will be slowed down by constrained financial report about the 11th International Conference on High astrophysics, detector and accelerator physics, computing, lens of this magazine, it would take a bold soul to claim support of high-energy physics.” Energy Accelerators in the September 1980 issue, pointed applications, and broader trends in the field. It is strik- that it isn’t worth a look.  Deciding where to build the next collider and getting out that seven decades in energy had been mastered in ing how much the field has advanced and specialised. international partners on board was also no easier in the 50 years of accelerator construction. Extrapolating to the Equally, it is heartening to find so many parallels with Further reading past, if the SPS was any guide. The September 1970 issue 21st century, he envisaged “a 20 TeV proton synchrotron today. Some are sociological: in October 1995 a report on The full Courier archive can be browsed at wrote that the “present impasse in the 300 GeV project” is and 350 GeV electron–positron linear colliders”. On CERN’s an ECFA study noted “much dissatisfaction” with long https://cds.cern.ch.

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TRIBUTE MURRAY GELL-MANN 1929–2019 TRIUTE URRA ELLANN 0

u o/ale chives h rc A h ltec roe/Ca Mun J seemed to feel as if he was in the shadow of Feynman, par- repeated correct intuition in the whole history of science. e as a ticularly with Feynman’s showmanship. When Feynman He tried to go on. He talked about “grand unifi cation strange died, Murray wrote a rather snarky obituary, saying of being in t he air”, and (along wit h many ot her physicists) mitre of MEMORIES Feynman: “He surrounded himself with a cloud of myth, d i s c u s s e d t h e p o s s i bi l it y t h at Q C D a n d t h e t h e or y o f w e a k gracios and and he spent a great deal of time and energy generating interactions might be unifi ed in models based on groups gregarios anecdotes about himself.” I never quite understood why such as SU(5) and SO(10). He considered supersymmetry. Murray – who could have gone to any university in the But quick validations of these theories didn’t work out, FROM world – chose to work at Caltech for 33 years in an offi ce though even now it’s still conceivable that some version two doors down from Feynman. of them might be correct. Murray cared a lot about what people thought of him, I have often used Murray as an example of the challenges CALTECH but wasn’t particularly good at reading other people. Yet, of managing the arc of a great career. From his twenties alongside the brush-off s and the strangeness, he could to his forties, Murray had the golden touch. His particular be personally very gracious. I remember him inviting me way of thinking had success after success, and in many several times to his house. He also did me quite a few favours ways he defi ned physics for a generation. By the time I Stephen Wolfram reflects on in my career. I don’t know if I would call Murray a friend, knew him, the easy successes were over. Perhaps it was though, for example, after his wife Margaret died, he and Murray more likely, it was just that the easy pickings from Gell-Mann’s complex character and I would sometimes have dinner together, at random res- his approach were now gone. He so wanted to succeed as his rivalry with Richard Feynman. taurants around Pasadena. It wasn’t so much that I felt of he had before, not just in physics but in other fi elds and Talented rivals Murray Gell-Mann (left) with Richard Feynman at Caltech in 1959. a diff erent generation from him (which of course I was). It endeavours. But he never found a way to do it – and always was more that he exuded a certain aloof tension, that made bore the burden of his early success. n t h e m id-1970 s, p a r t ic le p h y s ic s w a s h o t. Q u a r k s w e r e in quantum field theory called the beta function. His face Both would one not feel very sure about what the relationship really was. Though Murray is now gone, the physics he discovered will in. Group theory was in. Field theory was in. And so showed no recognition of what I was talking about, and make Murray Gell-Mann had an amazing run. For 20 years live on, defi ning an important chapter in the quest for our I much progress was being made that it seemed like I was getting slightly exasperated. Eventually I blurted surprisingly he had made a series of bold conjectures about how nature understanding of the fundamental structure of our universe.  t h e f u n d a m e nt a l t h e or y o f p h y s ic s m i g ht b e c lo s e at h a n d. out, “But, Murray, didn’t you invent this?” “Oh”, he said, childish m i g ht wor k – s t r a n g e n e s s, V-A t h e or y, SU(3), q u a r k s, Q C D  Right in the middle of all this was Murray Gell-Mann – s ud d e n l y muc h m or e c h a r m i n g, “Yo u m e a n g t i m e s t h e p s i comments – and in each case he had been correct, while others had This article draws on a longer tribute published on r e s p o n s i ble for n o t o n e, b ut m o s t, o f t h e le a p s o f i nt u it io n function. Why didn’t you just say that? Now I understand.” been wrong. He had one of the more remarkable records of www.stephenwolfram.com. about that had brought particle physics to where it was. There’d I c o u ld n e v e r q u it e fi g u r e o ut w h at it w a s t h at m a d e M u ray the other been other theories, but Murray’s, with their somewhat impressed by some people and not others. He would routinely e l a b or at e a n d a b s t r a c t m at h e m at ic s, w e r e a l w a y s t h e o n e s disparage physicists who were destined for great success, that seemed to carry the day. and would vigorously promote ones who didn’t seem so 300kW All Solid-State RF Amplifier It was the spring of 1978 and I was 18 years old. I’d been promising, and didn’t in fact do well. So when he promoted p u bl i s h i n g p a p e r s o n p a r t ic le p h y s ic s for a fe w y e a r s. I w a s me, I w as on t he one hand flat tered, but on t he ot her hand Model : CA500BW2-8085RP in England, but planned to soon go to graduate school in c o n c e r n e d a b o ut w h at h i s e n d or s e m e nt m i g ht r e a l l y m e a n. R&K Company Limited R&K provides the world’s most reliable high performance solid-state RF Power Amplifiers. t h e US, a n d w a s c h o o s i n g b e t w e e n C a lt e c h a n d P r i n c e t o n. One weekend afternoon, the phone rang. “This is Murray Feynman interactions AMPLIFIER DESIGN Gell-Mann”, the caller said, then launched into a mon- The interaction between Murray Gell-Mann and Richard ・Consists of four (4) rack-mounted 75kW SSAs. ologue about why Caltech was the centre of the universe Feynman was an interesting thing to behold. Both came ・Able to deliver 300kW via 4-way power combiner. for p a r t ic le p h y s ic s at t h e t i m e. P e r h a p s n o t a s s t a r-s t r uc k f r o m Ne w Yor k, b ut Fe y n m a n r e l i s h e d h i s “wor k i n g c l a s s” ・96-way radial combiner for final power combining as I should have been, I asked a few practical questions, New York accent while Gell-Mann affected the best pro- of 75kW SSA. which Murray dismissed. The call ended with something nunciation of words from any language. Both would make ・Long-term & highly reliable operation achieved li ke, “Well, we’d li ke to have you at Caltec h”. surprisingly childish comments about the other. I remember by protecting each final-stage transistor with built-in circulator at its output. I r e m e m b e r t h e e v e n i n g I a r r i v e d, w a n d e r i n g a r o u n d t h e Feynman insisting on telling me the story of the origin 96-way Radial Combiner Output Power Linearity ■Output Pulse empty fourth floor of Lauritsen Lab – the centre of Caltech of the word “quark”. He said he’d been talking to Murray 86 Frequency = 500MHz, Po = 300kW 85 X：50μs / DIV Y：200mV / DIV 84 FWD LIMIT 83 t h e or e t ic a l p a r t ic le p h y s ic s. T h e r e w e r e a l l s or t s o f n a m e s one F r id a y a b out t he s e hy p ot he t ic a l p a r t ic le s, a nd i n t he i r 82 81 80 79 I recognised on office doors, and there were two offices conversation they’d needed a name for them. Feynman told 78 77 76 75 t hat were obv iously t he la rgest: “M. G el l-M a n n” a nd “R. me he said (no doubt in his characteristic accent), “Let’s call 74 73 72

Output Power (dBm) 71 Frequency Fe y n m a n”. I n b e t w e e n t h e m w a s a s m a l l offic e l a b e l le d “H. them ‘quacks’”. The next Monday, he said, Murray came 70 69 499MHz 68 500MHz T uc k”, w h ic h b y t h e n e x t d a y I’d r e a l i s e d w a s o c c upie d b y to him very excited and said he’d found the word “quark” 67 501MHz -15 -10 -5 0 5 10 the older but very lively departmental assistant. in a novel by James Joyce. In telling this to me, Feynman Input Power (dBm) ■Pulse Rise ■Pulse Fall Frequency = 500MHz, Po = 300kW Frequency = 500MHz, Po = 300kW I never worked directly with Murray but I interacted with then went into a long diatribe about how Murray always X：200ns / DIV Y：200mV / DIV X：50ns / DIV Y：200mV / DIV him frequently while I was at Caltech. He was a strange seemed to think the names for things were so important. SPECIFICATION m i x t u r e o f g r a c io u s a n d g r e g a r io u s, t o g e t h e r w it h a u s t e r e “Having a name for something doesn’t tell you a damned Frequency Range : 500MHz±1MHz and combative. He had an expressive face, which would thing,” Feynman said. Feynman went on, mocking Mur- Output Power : 320kW @Peak, 300kW (min.) *Each rack-mounted amplifier section individually delivers 75kW. wrinkle up if he didn’t approve of what was being said. ray’s concern for things like what different birds are called. (75kW/rack ×4 outputs) Murray always grouped people and things he approved (Murray was an avid bird watcher.) Meanwhile, Feynman Pulse Width : 1μs～300μs (max.) of, and those he didn’t – to which he would often give had worked on particles that seemed (and turned out to Duty : 0～3% (max.) disparaging nicknames. (He would always refer to solid- b e) r e l at e d t o q u a r k s. Fe y n m a n h a d c a l le d t h e m “p a r t o n s”. R&K Company Limited Operation Mode : Class AB THE AUTHOR φ state physics as “squalid-state physics”.) Sometimes he M u r r a y i n s i s t e d o n a l w a y s r e fe r r i n g t o t h e m a s “p ut-o n s”. www.rk-microwave.com AC Supply Input : AC200V±10%／3 , 50／60Hz Stephen Wolfram 721-1 Maeda, Fuji-City, Shizuoka, 416-8577 Japan Size : (W)2240mm×(D)1300mm×(H)1510mm would pretend that things he did not like simply did not Even though in terms of longstanding contributions to founder and CEO of Tel:+81-545-31-2600 Fax:+81-545-31-1600 Email:[email protected] exist. I remember once talking to him about something particle physics, Murray was the clear winner, he always .

34 CERN COURIER JULY/AUGUST 2019 CERN COURIER JULY/AUGUST 2019 35

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High performance analogue OPINION signal transmission over fibre montena technology sa VIEWPOINT 80 Hz – 3.5 GHz bandwidth 1728 Rossens · Switzerland montena.com R Remote controlled input attenuator and preamplifier R Compact shielded module with embedded battery R Available in point-to-point and multilink versions TYPICAL APPLICATIONS Reflections on Granada Fast impulse or high bandwidth analogue signal transmission over long distance. Measurements in physics research labs, particle accelerators, high-voltage substations, railways, etc. Sandbox Studio, Chicago, courtesy of Symmetry of courtesy Chicago, Studio, Sandbox The open symposium of the European MOL2000T Strategy for Particle Physics stimulated much lively discussion about the future of particle physics and the central role of CERN, writes Eckhard Elsen.

Nearly 70 years ago, before CERN was magazine CERN

ink established, two models for European l KEEP collaboration in fundamental physics were on the table: one envisaged open-

ptical ing up national facilities to researchers o from across the continent, the other the creation of a new, international research centre with world-leading facilities. Dis- cussions were lively, until one delegate Modular polygone.ch Eckhard Elsen pointed out that researchers would go to CALM is CERN director for wherever the best facilities were. Multifaceted The European Strategy Group faces a monumental challenge in plotting research and From that moment on, CERN became a course for the future of high-energy physics. computing. an accelerator laboratory aspiring to be at the forefront of technology to ena- Nevertheless, however precise proton- strategy for European particle physics. ble the best science. It was a wise deci- proton physics becomes, it will still fall With all the available technology options sion, and one that I was reminded of short in some areas. To fully understand and open questions in physics, there’s no while listening to the presentations at the absolute width of the Higgs, for exam- doubt that the future should be bright. The the open symposium of the European ple, a lepton machine will be needed, and European Strategy Group, however, has Strategy for Particle Physics in Gra- no fewer than four implementations were a monumental challenge in plotting an nada, Spain, in May. Because among the discussed. So, one key conclusion is that if a fford a bl e c o u r s e t o pr o p o s e t o t h e CERN conclusions of this very lively meeting we are to cover all bases, no single facility Council in March next year. was the view that providing world- will suffice. One way forward was pre- There were calls for CERN to diversify leading accelerator and experimental sented by the chair of the Asian Committee and lend its expertise to other areas of facilities is precisely the role the com- for Future Accelerators Geoff Taylor, who research, such as gravitational waves: munity needs CERN to play today. advocated a lepton machine for Asia while one speaker even likened interferom- There was huge interest in the sym- Europe would focus on advancing the eters to accelerators without beams. In posium, as witnessed by the 600-plus hadron frontier. terms of the technologies involved, that participants, including many from the Interest in muon colliders was rekin- statement stands up well to scrutiny, nuclear and astroparticle physics com- dled, not least because of some recent and it is true that technology devel- munities. The vibrancy of the field was reconsiderations in muon cooling (CERN oped for particle physics at CERN can fully on display, with future hadron col- Courier July/August 2018 p19). The great help the advancement of other fields. l id e r s o ffe r i n g t h e bi g g e s t l e a p i n e n e r gy a n d r e c e nt pr o g r e s s o f pl a s m a-w a k e fie l d CERN already formally collaborates reach for direct searches for new physics. accelerators, including AWAKE at CERN, with organisations like ITER and the ESS, Precision electroweak studies at the few calls for further research in this field so sharing our innovation and expertise. per cent level, particularly for the Higgs as to render the technology usable for However, for me, the strongest message particle, will obtain sensitivities for sim- particle physics. Methods of dark-matter from Granada is that it is CERN’s focus ilar mass scales. The LHC, and soon the searches abound and are an important on remaining at the forefront of particle CERN needs to High-Luminosity LHC, will go a long way element of the discussion on physics physics that has enabled the Organization r em a i n t r ue to towards achieving that goal of precision. beyond colliders, using single beams to contribute to a diverse range of fields. its founding Indeed, it’s remarkable how far the LHC at CERN. CERN needs to remain true to that found- vision of experiments have come in overturning The Granada meeting was a town meet- ing vision of being a world-leading centre b ei ng a world- the old adage that hadrons are for discov- ing on physics. Yet, it is clear to all that we for accelerator technology. That is the ery and leptons for precision – the LHC can’t make plans solely on the basis of the starting point. From it, all else follows. leading centre has established itself as a precision tool, available technology and a strong physics for accelerator and this is shaping the debate as to what case, but must also consider factors such  This article was originally published technology kind of future we can expect. as cost and societal impact in any future in the CERN Bulletin.

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Lessons from LEP

The Large Electron Positron collider (LEP) changed particle physics, and CERN, forever. Former Director-General Herwig Schopper describes what it took to make LEP happen. S Hertzog/CERN-PHOTO-201906-169-6 Hertzog/CERN-PHOTO-201906-169-6 S When was the first LEP proposal advised by some senior colleagues to made, and by whom? resign because it was not possible to Discussions on how to organise a build LEP on a constant budget. So “world accelerator” took place at a we found another idea: make advance pre-ICFA committee in New Orleans in payments and create debts. Council the early 1970s. The talks went on for a said we can’t make debts with a long time, but nothing much came out bank, so we raided the CERN pension of them. In 1978 John Adams and Leon fund instead. They agreed happily Van Hove – the two CERN Director- since I had to guarantee them 6% Generals (DGs) at the time – agreed to interest, and as soon as LEP was built build an electron–positron collider at we started to pay it back. With the CERN. There was worldwide support, LHC, Carlo Rubbia had to do the same but then there came competition (t he only difference w as t hat Council from the US, worried that they said he could go to a bank). CERN is might lose the edge in high-energy still operating within essentially the physics. Formal discussions about a same constant budget today (apart Superconducting Supercollider (SSC) from compensation for inflation), had already begun. While it was open with the number of users having to international contribution, Ronald more than doubled – a remarkable Reagan’s “join it or not” approach to achievement! To get LEP approved, I the SSC, and other reasons, put other also had to say to Council that CERN count ries off t he project. would fund the machine and others would fund the experiments. Before Was there scientific consensus for LEP, it was usual for CERN to pay for a collider four times bigger than experiments. We also had to stop anything before it? several activities like the ISR and the Yes. The W and Z bosons hadn’t yet Looking forward Herwig Schopper believes that the next BEBC bubble chamber. So LEP changed been discovered, but there were machine has to be a world facility. CERN completely. already strong indications that they were there. Measuring the electroweak with the idea to make it 22 km in How do LEP’s findings compare with bosons in detail was the guiding force circumference. At that time CERN had a what was expected? for LEP. There was also the hunt for “basic” programme (which all Member It was wonderful to see the W and the Higgs and the , yet there States had to pay for) and a “special” Z discovered at the SPS while LEP Compact magnet was no guidance on the masses of programme whereby additional funds was being built. Of course, we were these particles. LEP was proposed in were sought. The latter was how the disappointed that the Higgs and the Photo: Perry Nordeng two phases, first to sit at the Z pole and Intersecting Storage Rings (ISR) and top were not discovered. But, look, segments for MAX IV then the WW threshold. We made the the (SPS) these things just weren’t known then. straight sections as long as possible so were built. But the cost of LEP made When I was at DESY, we spent 5 million High quality magnets and coils, designed and we could increase the energy during some Member States hesitate because Deutsche Marks to increase the radio- manufactured by Swedish engineering in order to the LEP2 phase. they were worried that it would eat too frequency power of the PETRA collider I was advised provide the best solutions for all your needs! We much into the resources of CERN and because theorists had guaranteed by some senior take pride in close collaborations with the customer, W hat about political consensus? national projects. that the top quark would be lighter The first proposal for LEP w as init ially colleagues than 25 GeV! At LEP2 it was completely whether it is for research or industry. refused by the CERN Council because How was the situation resolved? to resign unknown what it would find. it had a 30 km circumference and cost After long discussions, Council said: b e c aus e it w a s  SCANDITRONIX-MAGNET.SE 1.4 billion Swiss Francs. When I was yes, you build it, but do so within a not possible W hat is LEP’s physics legacy? appointed DG in February 1979, they constant budget. It seemed like an These days, there is a climate where asked me to sit down with both current impossible task because the CERN to build LEP everything that is not a peak is not DGs and make a common proposal, budget had peaked before I took over on a c on st a nt a discovery. People often say “not which we did. This was the proposal and it was already in decline. I was budget much came out from LEP”. That is

CERN COURIER JULY/AUGUST 2019 39

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OPINION INTERVIEW

completely wrong. What people forget You were born before the Schrödinger is that LEP changed high-energy What people forget is that LEP equation and retired when LEP switched physics from a 10% to a 1% science. changed high-energy physics on in 1989. What have been the highs Apart from establishing the existence and lows of your remarkable career? of t hree neut rino flavours, t he LEP from a 10% to a 1% science I was lucky in my career to be able experiments enabled predictions of the to go through the whole of physics. top-quark mass that were confirmed My PhD was in optics and solid-state at Fer milab’s Tev at ron. This is because the policy of management was not to physics, then I later moved to nuclear LEP w as measuring t he radiat ive explain what we are doing because and par t icle physics. So I’ve had t his corrections – the essential element it is “too complicated”! I was very fantastic privilege. I still believe in that shows the Standard Model is surprised to learn this when I arrived the unity of physics in spite of all the a renor malisable t heor y, as show n as DG, so we had many hundreds of specialisation that exists today. I am theoretically by ’t Hooft and Veltman. meetings with the local community. glad to have seen all of t he highlights. It also showed that the strong coupling There was a misunderstanding about Witnessing the discovery of parity

constant, as, runs with energy and the word “nuclear” in CERN’s name violation while I was working in allowed the coupling constants of all – t hey t hought we were involved nuclear physics was one. the gauge forces to be extrapolated to in generating nuclear power. That the Planck mass – where they do not fortunately has completely changed How do you see the future of curiosity- meet. To my mind, this is the most and CERN is accepted in the area. driven research, and of CERN? concrete experimental evidence that What is different concerns the The future of high-energy physics is the Standard Model doesn’t work, that physics. We are in a situation more to combine w it h ast rophysics, because there is something beyond it. similar to the 1970s before the the real big questions now are things famous J/ψ discover y when we had like dark matter and dark energy. How did the idea come about to put a no indications from theory where This has already been done in a sense. proton collider in the LEP tunnel? to go. People were talking about all Originally the idea in particle physics When LEP was conceived, the Higgs sorts of completely new ideas back was to investigate the micro-cosmos; was far in the future and nobody was then. Whatever one builds now is now we find out t hat measuring t he really talking about it. When the LEP penetrating into unknown territory. micro-cosmos means investigating tunnel was discussed, it was only the One cannot be sure we w ill find matter under conditions that existed competition with SSC. The question something because there are no nanoseconds after the . Of was: who would win the race to go predictions of any thresholds. course, many questions remain in to higher energy? It was clear in the particle physics itself, like neutrinos, long run that the proton machine What wisdom can today’s decision- matter–antimatter inequality and the Mass Spectrometers would win, so we had the famous makers take from the LEP experience? real unificat ion of t he forces. workshop in Lausanne in 1983 where In the end I think that the next Wit h LEP and t he LHC, t he number we discussed the possibility of putting machine has to be a world facility. of outside users who build and operate a proton collider in the LEP tunnel. It The strange thing is that CERN t he e x periments increased drast ically, for Fusion Research was foreseen then to put it on top of formally is still a European lab. There so the physics competence now rests LEP and to have them running at the are associates and countries who to a large e x tent w it h t hem. CERN’s same time. With the LHC, we couldn’t cont ribute in k ind, whic h allows t hem competence is mainly new tec hnolog y, compete in energy with the SSC so to participate, but the boring things both for experiments and accelerators. DLS Series we went for higher luminosities. But li ke staff salaries and elect ricit y have At LEP, c heap “concrete” instead of when we looked into t his, we realised to be paid for by the Member States. iron mag nets were used to save on we had to make the tunnel bigger. One therefore has to find out whether investment, and coupled RF cavities The original proposal, as approved by the next collider can be built under a to use power more efficient ly were Council in October 1981, had a tunnel constant budget or whether one has invented, and later complemented size of 22 km and making it bigger was to change the constitutional model by superconducting cavities. New a big problem because of the geology – of CERN. In t he end I t hin k t he ne x t detector technologies following the basically we couldn’t go too far under collider has to be a proton machine. CERN t radit ion of Char pa k t ur ned t he the Jura mountains. Nevertheless, Maybe the LEP approach of beginning LEP experiments into precision ones. I decided to go to 27 km against the with an electron–positron collider in This line w as followed by t he LHC, advice of most colleagues and some a new tunnel would work. I wouldn’t w it h t he first large-scale use of high- advisory committees, a decision that exclude it. I don’t believe that an field superconducting magnets and delayed LEP by about a year because of electron–positron linear collider superfluid-helium cooling technology. the water in the tunnel. But it is almost would satisfy requests for a world Whatever happens in elementar y forgotten that the LEP tunnel size was machine as its energy will be lower par t icle physics, tec hnolog y w ill remain only c hosen in v iew of t he LHC. than for a proton collider, and because one of CERN’s key competences. Above it has just one interaction point. a nd be yond element a r y pa r t ic le physics, Are there parallels with CERN Whatever the next project is, it should CERN has become suc h a sy mbol and today concerning what comes next be based on new technology such as big success for Europe, and a model for after the LHC? higher field superconducting magnets, worldwide international cooperation, Yes and no. One of t he big differences and not be just a bigger version of the t hat it is wor t h a large polit ical effor t to compared to t he LEP days is t hat, bac k LHC. Costs have gone up and I think guarantee its long-term future. then, the population around CERN the next collider will not fly without did not know what we were doing – new technologies. Interview by Matthew Chalmers editor.

40 CERN COURIER JULY/AUGUST 2019 W www.HidenAnalytical.com E [email protected]

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DLS-20 Unique dual-zone switching ultra- OPINION high resolution mass spectrometer for the analysis of hydrogen and helium isotopes LETTERS and light gases

 Industry first 20 mm rod diameter quadrupole mass filter for Completing the proton picture Adjusting cosmic-ray origins Dominguez/CERN-HOMEWEB-PHO-2019-065-1 D ultra-high mass resolution Your article “The proton laid bare” (CERN I recently read your very nice article on 10000 HD+ Courier May/June 2019 p38) covered beau- IceCube from last year (CERN Courier 9000  Software switchable dual-zone RF power supply for Zone H 8000 ultra-high resolution 1-20 amu operation and Zone I ultra-high tifully and to a large extent the subject September 2018 p7), but found the title 7000 under the given heading. For complete- “IceCube neutrino points to origin of 6000 stability 1-200 amu operation 5000 ness, we in the COMPASS collaboration cosmic rays” to be very misleading. By + Region2 : c/s Region2 4000 3He  0.006 amu mass separation in real time at CERN wish to add the following addi- far, the majority of cosmic rays that we 3000 tional information. detect on Earth are from our own galaxy, 2000  Sensitivity of both He in D2 and D2 in He is 1 ppm 1000 A state-of-the-art description of the and are much lower energy than those 3 0  He quantification in HD DLS-20 3.010 3.015 3.020 3.025 3.030 3.035 field should address the structure of the that IceCube is sensitive to. There are mass : amu proton also in terms of its transverse many things that we don’t understand degrees of freedom. These enter with the about the origin of cosmic rays in our same relevance as the described longi- own galaxy, for example whether the DLS-10 Mass spectrometer specifi cally tudinal structure, and complete the 3D heaviest r-process cosmic rays origi- picture of the nucleon. nate in supernovae or in binary neutron developed for the research and COMPASS has a world-leading role in star mergers, and these results do not quantifi cation of light gases and hydrogen t h i s fie l d. D u r i n g t h e p a s t 20 y e a r s itcon- address those. This does not in any sense tributed numerous results on the study of diminish the importance of the IceCube isotopes by mass helicity distributions, the gluon contri- and gamma-ray results. But in the future bution to the spin of the proton, and the it would be better to qualify it by saying 3D proton structure using polarised Drell- “extra-galactic” cosmic rays.  1-10 amu mass range Yan and hard semi-inclusive or exclusive  Zone H ultra-high resolution operation for the separation and processes, as well as transversity and Robert Binns Washington University in quantification of hydrogen and helium isotopes transverse-momentum-dependent PDFs. St. Louis, US.  Sensitivity of both He in D and D in He is 10 ppm Finally, in terms of addressing “The 2 2 proton spin crisis” (May/June, p40), the The music of physics currently operational COMPASS experi- In an obituary of Nobel prize-winning ment is certainly to be mentioned along- chemist published recently side work at Jefferson Laborator y. in Nature, we learned that he remained an impressive amateur pianist, “sometimes DLS-10 Oleg Denisov INFN and Jan Friedrich playing Mozart’s concertos after scien- TUM, COMPASS spokespersons. t i fic m e e t i n g s.” It r e m i n d e d m e o f We r n er He i s e n b e r g’s pi a n o pr o fic i e n c y d e s c r i b e d Colourful Too much particle physics? Proton radius still puzzles in this magazine (CERN Courier Jan/Feb complexity I noticed that the Sciencewatch section DLS-1 Mass spectrometer for real-time Your article “Solving the proton-radius 2005 p41). To celebrate Heisenberg’s 60th An artist’s has disappeared from the CERN Courier. quantitative analysis of complex gas and puzzle” (CERN Courier May/June 2019 p42) birthday, a small orchestra was brought impression of the I have read about all the changes that mentioned some recent extractions of together to accompany him in performing proton’s innards. are being introduced in the magazine vapour mixtures in fusion applications the proton charge radius from electronic Mozart’s Piano Concerto, K488. (CERN Courier December 2018 p56), but I hydrogen spectroscopy. These are more Former CERN Director-General Victor am still left wondering about this deci- consistent with the value extracted Weisskopf could even act as a conductor, sion. I think it was an interesting and  1-100 amu mass range from muonic hydrogen, 0.8409(4) fm, as he did during his retirement celebra- enriching section. Without it, while still  Software driven recipes using threshold ionisation mass than the most recent CODATA value of tion at MIT in 1974. For Weisskopf, music remaining very interesting, the maga- spectrometry (TIMS) for the real-time quantification of 0.8751(61) fm. and physics served as sanctuary: “When zine feels more “arid” to me. Does it all hydrogen and helium isotopes and deuterated hydrocarbons Unfortunately, another recent extrac- life is hard, there are two things which have to be particle physics 100%, even tion from electronic hydrogen spectros- make it worth living: Mozart and quantum for the Courier?  Sensitivity of D2 in He of 100 ppm copy by Fleurbaey et al. (Phys. Rev. Lett. mechanics”. Reflecting on the phenom- 120 183001) was omitted in the article; enon in an essay, Weisskopf wrote: True Alexandre Sole The Open University. t h e v a lu e t h e y fi n d i s 0.877(13) fm, which enough, music is “irrational” in the sense is more consistent with CODATA than there is no “objective” way to prove what Editor’s reply muonic hydrogen. musical passage is right or wrong. But the You are not alone in questioning Science- Even more exciting, we now have two structure of music is related to structure in watch’s retirement. As another reader DLS-1 different groups, one in Paris and one in science, especially in . I refer put it: “There’s something wonderful Garching, that have measured the same to symmetry, repetition of a passage in a in reading about the subtleties of elec- 1 S–3S t r a n s it i o n b ut e x t r a c t d i ffe r e nt v al- d i ffe r e nt k e y, i n v e r s i o n s o f t u n e s a n d m any troweak symmetry breaking one min- Hiden Analytical Ltd, 420 Europa Boulevard, Warrington WA5 7UN ues of the proton charge radius. Thus, the other topological features. No wonder sci- ut e, t h e n t u r n i n g t h e p a g e t o fi n d a s t or y proton-radius puzzle still stands. entists are attracted by the fugues of Bach. about the sex lives of lizards.” What can T +44 [0] 1925 445 225 F +44 [0] 1925 416 518 we say? Only that all feedback is taken on Gil Paz Wayne State University, Min-Liang National Chung Hsing board as we strive to keep CERN Courier Michigan, US. University, Taiwan. relevant for a seventh decade and beyond.

W www.HidenAnalytical.com E [email protected] CERN COURIER JULY/AUGUST 2019 43

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CERNCOURIER.COM OPINION REVIEWS

M Brice/CERN-PHOTO-201501-003-9M Handle with care Radiation measurement tools and samples.

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MY Radio-euphoria rebooted?

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CMY physics, and biochemistry and biology. I i r r a d i a t i o n d o e s n o t a ffe c t hu m a n h e a l th. K Radiation: Fundamentals, Applications, Risks and would first, however, like to draw atten- It is understandable that the greater tion to the rather novel section ‘Quantum part of the book, as for any textbook, is Safety laws and a living cell’. a kind of compilation, however, it does By Ilya Obodovskiy Quite a long time after the discovery discuss several quite original issues. of X-rays and radioactivity, the public Here I will point out just one. To my Elsevier was overwhelmed by “X-ray-mania and knowledge, Obodovskiy is the first to radio-euphoria”. But after World War draw attention to the fact that deep in Ilya Obodovskiy’s new book is the most II – and particularly after the Japanese the seas, oceans and lakes, the radiation detailed and fundamental survey of the vessel Fukuryū-Maru experienced the background is two to four orders of mag- subject of radiation safety that I have radioactive fallout from a thermonuclear nitude lower than elsewhere on Earth. ever read. explosion at Bikini Atoll – humanity The author posits that one of the reasons The author assumes that while none of got scared. The resulting radio-phobia for the substantially higher complexity his readers will ever be exposed to large determined today’s commonly negative and diversity of living organisms on doses of radiation, all of them, irrespec- attitudes towards radiation, radiation land could be the higher levels of ionis- tive of gender, age, financial situation, technologies and nuclear energy. In ing radiation. profession and habits, will be exposed to this book Obodovskiy shows that radio- In the last chapter the author gives low doses throughout their lives. There- phobia causes far greater harm to public a detailed comparison of the various fore, he reasons, if it is not possible to health and economic development than sources of danger that threaten people, get rid of radiation in small doses, it is the radiation itself. such as accidents on transport, smoking, necessary to study its effect on . The risks of ionising radiation can alcohol, drugs, fires, chemicals, terror Obodovskiy adopts a broad approach. only be clarified experimentally. The and medical errors. Obodovskiy shows Addressing the problem of the narrowing author is quite right when he declares that the direct danger to human health of specialisations, which, he says, leads that medical experiments on human from all nuclear applications in industry, to poor mutual understanding between beings are ethically evil. Nevertheless, power production, medicine and research t h e d i ffe r e nt fie l d s o f s c i e n c e a n dinus- a large group of people have received is significantly lower than health hazards try, the author uses inclusive vocabulary, s m a l l d o s e s. A n a n a l y s i s o f t h e e ffe c t o f from every non-nuclear source of danger. simultaneously quoting different units of radiation on these groups can offer basic measurement, and collecting informa- information, and the author asserts that Vladislav Grigoriev Moscow Engineering tion from atomic, molecular and nuclear in most cases results show that low-dose Physics Institute.

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Ultra High Performance OPINION REVIEWS Silicon Drift Detector PEOPLE From My Vast Repertoire … masses. The various ® FAST SDD Guido Altarelli’s Legacy private pictures, which CAREERS include a selection from Count Rate = >1,000,000 CPS By Stefano Forte, Aharon Levy and his family and friends, Giovanni Ridolfi (editors) make the presence of Guido ubiquitous even World Scientific The True State-of-the-Art though his personality emerges more vividly • New in-house manufacturing “From my vast repertoire …” is a rather in some contributions High-energy networking • Lower noise peculiar opening to a seminar or a lecture. than others. Guido’s The late CERN theorist Guido Altarelli prob- readiness to debate the relevant physics issues • Lower leakage current ably intended it ironically, but his repertoire of his time is one of the recurring themes of Two years since it was established, the CERN Alumni Network is proving a valuable careers resource, • Better charge collection was indeed vast, and it spanned the whole of this volume; the interpretation of monojets the “famous triumph of quantum field the- at the SPS, precision tests of the Standard especially for young physicists who move out of academia, write Laure Esteveny and Rachel Bray. Compatible with EPICS tools & libraries ory,” as Sidney Coleman puts it in his classic Model at LEP, the determination of the strong monograph Aspects of Symmetry. There can coupling constant, and even the notion of in decreasing order: < = 20 25 mm2 FAST SDD® 55Fe Spectrum be little doubt that a conspicuous part of this naturalness, are just a few examples. research 21–25 2 25 mm FAST SDD® triumph must be ascribed to the depth and While lecturing at CERN in 2005, Nobel 26–30 800,000 230K, Tpk = 8 µs 1,000,000 higher education other fields breadth of Altarelli’s contributions: the HERA prize-winning theorist David Gross out- Peak to 1 keV background Mn Kα computer software (71) 31–35 26,000:1 100,000 programme at DESY, the LEP and LHC pro- lined some future perspectives on physics, 36–40 Mn Kβ information technology and services 600,000 grammes at CERN, and indeed the current and warned about the risk of a progressive 41–45 10,000 financial services paradigms of the strong and electroweak balkanisation. The legacy of Guido stands 46–50

COUNTS government administration 400,000 1,000 interactions themselves, bear the unmistaka- out among the powerful antidotes against a 51–55 122 eV FWHM management consulting ble marks of Guido’s criticism and inspiration. never-ending fission into smaller subfields. 56–60 100 internet From My Vast Repertoire … is a memorial He understood which problems are ripe to 61–65 age range of members 200,000 mechanical or industrial engineering 66–70 10 volu me t h at e nc omp a s s e s t he s c ie nt i fic a nd study and which are not, and that is why he telecommunications 71–75 human legacies of Guido. The book consists was able to contribute to so many concep- 0 1 defence and space 76–80 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 of 18 well-assorted contributions that cover tually different areas, as this monograph Energy (keV) electrical/electronic manufacturing 81–85 his entire scientific trajectory. His wide clearly shows. The lesson we must draw from 86–90 Resolution vs Peaking Time semiconductors 180 interests, and even his fear of an untimely Guido’s achievements and his passion for 2 aviation and aerospace 25 mm death, are described with care and respect. science is that fundamental physics must be 04200 00 6001800 000 computer and network security 170 For these reasons the efforts of the authors inclusive and diverse. Lasting progress does and editors will be appreciated not only by not come by looking along a single line of 160 Standard SDD his friends, collaborators and fellow practi- sight, but by looking all around where there Variety CERN alumni by employment sector (left) and the age range of members (right). ® 150 FAST SDD t ioners in t he field, but also by younger sci- are mature phenomena to be scrutinised at entists, who will find a timely introduction the appropriate moment. CERN has 65 years of history and to do so. Three highly successful strate the impact of experience “It’s great that CERN values the 140 to the current trends in particle physics, from more than 13,000 international “Moving out of academia” events gained at CERN, we launched a network of physicists past and on (eV FWHM @ 5.9 keV) @ 5.9 FWHM on(eV ti the high-energy scales of collider physics Massimo Giovannini CERN and INFN users. The CERN Alumni Network, have been held at CERN with the campaign to invite those who have present who’ve passed through 130 Resolution (eV FWHM @ 5.9 keV)

Resolu to the low-energy frontier of the neutrino Milano-Bicocca, Italy. launched in June 2017 as a strategic t h e m e s fi n a n c e, bi g d a t a a n d i ndus- already signed up to update their or been based at the lab. The net- 120 objective of the CERN management, trial engineering. Each involved profiles concerning their profes- work has already led to some very 0.000 1.00 1 2.00 2 3.00 3 4.00 4 5.00 5 Peaking Time (μs) existence, and the sub- now has around 4600 members inviting a panel of alumni work- sional and educational experience. useful contacts for me,” writes for- Peaking Time (µs) Signatures of the Artist ject of a glut of searches spanning all parts of the world. ing in a specific field to give candid Increasing alumni interactions, mer summer student Matin Durrani, By Steven Vigdor Options: for physics beyond the Alumni pursue careers across many and pragmatic advice, and was very engagement and empowerment is now editor of Physics World maga- Oxford University Press Standard Model. fields, including industry, econom- well attended by soon-to-be CERN one of the most challenging objec- zine. “Best wishes from Guyancourt 2 2 • 25 mm active area collimated to 17 mm Taking no position on ics, information technology, medi- alumni, with more than 100 people tives at this stage, as we are compet- (fi r s t o ffic e) a s w e l l a s f r o m Va lenci- • 70 mm2 collimated to 50 mm2 MC Escher’s 1941 woodcut Plane-Filling Motif the existence of a creator c i n e a n d fi n a n c e. S e v e r a l h a v e g one at each event. In January the alumni ing with many other communities e n n e s (s e c o n d o ffic e) a n d o f c o u r se • Windows: Be (0.5 mil) 12.5 µm, or with Reptiles depicts two tessellating tetra- artist per se, Vigdor’s aim on to launch successful start-ups, network took part in an academia/ and with mobile apps such as Face- Stręgoborzyce (my family home). pods, one black and one white, with inter- is rather to complement some of them directly applying industry event titled “Beyond the book, WhatsApp and LinkedIn. Let’s grow and grow and show C Series (Si3N4) twined legs and feet on the adjacent sides. books that speculate on CERN-inspired technologies. Lab – Astronomy and Particle Phys- One very effective means for where we are after our experience • TO-8 package fits all Amptek configurations R e fle c t t h e i m a g e h or i z o nt a l l y a n d v e r t ic aly, new theories with an exposition of the “pains- So far, around 350 job opportu- ics in Business” at the newly inau- empowering local alumni commu- with CERN,” writes former techni- • Vacuum applications and the result is a photo negative: maximal taking and innovative” efforts of generations nities, posted by alumni or compa- gurated Higgs Innovation Centre at nities are regional groups. At their cal student Wojciech Jasonek, now a parity violation. A black–white transforma- of experimentalists to establish the weird n ie s a w a r e o f t h e s k i l l s a n d pr o fi l e s the University of Edinburgh. own initiative, members have cre- mechanical engineering consultant. tion – charge conjugation in the metaphor and wonderful physics we know. His book is a developed at CERN, have been pub- ated seven of them (in Texas, New After two years of existence we that inspired Steven Vigdor’s book – and, as romp from quantum mixing to the apparent lished on the alumni.cern platform. The data challenge York, London, Eindhoven, Swiss can say that the network is firmly in nature, we return to the original. Well, metastability of the vacuum (given current Approximately 25% of the jobs The network is still in its early days Romandie, Boston and Athens) and taking root and that the CERN almost. We can tell the difference from the measurements of the Higgs and top masses), posted are for software developer/ but has the potential to expand two more are in the pipeline (Vienna Office of Alumni Relations has position and colouration of Escher’s stylised with excursions into cosmology, biology and engineer positions, 16% for data much further. Improving the num- and Zurich). Their main activities are seen engagement and interactions initials in the corner. The only imperfection metaphysics. The intended audience is univer- science and 15% for IT engineering ber of alumni who have provided to hold events ranging from a simple between alumni growing. Anyone is the signature of the artist. sity students. As they cut their way through a positions. Several members have data (currently 37%) is an important drink to getting to know each other who has been (or still is) a user, Vigdor’s idea is that such deviations from jungle of mathematical drills in 19th-century already been successful in finding aim for the coming years. Knowing at more formal events, for example associate, fellow, staff or student 40 Years of perfect symmetry are not in fact “bugs”, physics, many lose sight of the destination. employment through the network. where our alumni are located and as speakers in STEM-related fields. at CERN, is eligible to join the net- Products for Your Imagination but are beautiful and essential. In the case Cheerful and down to earth, this book offers Another objective of the alumni their current professional activity One of the most rewarding work via alumni.cern. of CP violation – an essential ingredient in an invigorating glimpse through the foliage. programme is to help early-career allows us to reach out to them with aspects of running the network ® AMPTEK Inc. Sakharov’s baryogenesis recipe – the art- physicists make the transition from relevant information, proposals or has been getting to know alumni Laure Esteveny and Rachel Bray [email protected] ist’s signature is indispensable to our very Mark Rayner CERN. academia to industry if they choose requests. Recently, to help demon- and hearing their varied stories. CERN Office of Alumni Relations. www.amptek.com

46 CERN COURIER JULY/AUGUST 2019 CERN COURIER JULY/AUGUST 2019 47

CCJulAug19_Reviews_v2.indd 46 27/06/2019 15:23 CCJulAug19_Careers_v4.indd 47 28/06/2019 08:54 CERNCOURIER www. V o l u m e 5 9 N u m b e r 4 J u l y /A u g u s t 2 0 1 9 CERNCOURIER.COM CERNCOURIER.COM PEOPLE CAREERS RECRUITMENT Appointments and awards PI ANL high-precision measurements of novel experiments, test- of the cosmic microwave beam operations and analyses, For advertising enquiries, contact CERN Courier recruitment/classified, IOP Publishing, Temple Circus, Temple Way, Bristol BS1 6HG, UK. background temperature and to data analyses and their final Te l +4 4 (0)1 17 930 1 264 E-m a i l s a le s@c e r nc ou r ie r.c om. polarisation anisotropies. theoretical interpretations”. Please contact us for information about rates, colour options, publication dates and deadlines. The Gribov Medal for Finally, the 2019 EPS HEP outstanding work by a young Outreach Prize was awarded to

researcher in theoretical particle R Appleby physics was awarded to Douglas Stanford of the Institute for New head for Oak Ridge physics Advanced Study in Princeton Physicists and the Centre de The Department of Energy’s Oak (below) “for his pioneering recherches mathématiques.

Ridge National Laboratory has L A Cicero The prize recognizes Gomis “for named Marcel Demarteau (above) his broad range of important as director of its physics division. contributions to string theory and Demarteau was previously at strongly coupled gauge theories, Argonne National Laboratory, including the pioneering use where he directed the high- Rob Appleby of the University of non-local observables, the energy physics division with a of Manchester (above), Chris exact computation of physical programme ranging from studies Edmonds of the University of quantities in quantum field at the LHC to investigations Liverpool (below) and Robyn theory, and the unravelling of the using the South Pole Telescope work on and its Watson of Bolton Sensory Support non-perturbative dynamics of in Antarctica. He was previously relation to the near-horizon Service for their project “Tactile gauge theories.”

at Fermilab for nearly 20 years, dynamics of black holes”. The T Palin where he conducted detector R&D Young Experimental Physicist Innovative spirit recognised and served in leadership roles for Prize for outstanding work of The inaugural Oed prize, The Department of Physics at Universidad de los Andes (Uniandes), Bogotá, is seeking to fill a tenure-track the Dø experiment and worked on early-career researchers was established by the Institut Laue- faculty position in experimental High Energy Physics. Uniandes is a private university, which strives for the CMS experiment at the LHC. awarded to Josh Bendavid of Langevin in Grenoble, has been excellence in both teaching and research. According with the QS academic ranking, Uniandes is positioned Demarteau succeeds David Dean. CERN “for outstanding and awarded to Rui de Oliveira of CERN in the top ten universities in Latin America. Applicants should have a Ph.D. degree in this field of research with innovative contributions to (below) for his major contribution EPS prizes galore detector operations, software in the development of micro- postdoctoral experience in hardware and software development and implementation. The European Physical Society development, data analysis pattern gas detectors. The prize (EPS) has awarded the CDF and Dø and detector upgrades of the aims to promote an innovative All professors in our Department are required to participate in teaching a variety of undergraduate and collaborations at Fermilab with CMS experiment” and Lesya Collider”, which brings particle spirit and the ability to solve graduate courses in physics, including physics major requirements, and elective courses related to the the 2019 High Energy and Particle Shchutska of EPFL Lausanne physics to blind and visually technical challenges, which were research activities of the professors. The new faculty member will be expected to participate in institutional Physics Prize for the discovery EPFL impaired schoolchildren through at the origin of the micro-strip development activities in our Department and at the University level, outreach and international collaborations. of the top quark and the detailed touch and sound. The project has gas chamber invented by Anton measurement of its properties. run at many sites across the UK Oed in the late 1980s (see p57). The selected candidate is invited to join the High Energy Physics group at Universidad de los Andes. The The EPS awards the prize every and will be visiting CERN in the CERN-GE-1004075-01 group collaborates with the CMS experiment at the LHC, and has an intensive research program in particle two years for an outstanding autumn of 2019. contribution in an experimental, physics phenomenology and interdisciplinary detector applications. It is preferable if the new faculty member theoretical or technological area. Gomis wins Canadian award can contribute in more than one of these areas. Also, the group is open to new research lines and projects The 2019 Giuseppe and Jaume Gomis of the Perimeter in experimental high energy physics that the new faculty member may bring. Our institution is interested in Vanna Cocconi Prize for an Institute in Canada (top highly motivated professors with an interdisciplinary research approach and commitment to teaching. More outstanding contribution (above) “for outstanding right) has been awarded this information about the department research lines and experimental and computing facilities can be found at: to particle astrophysics and year’s Prize for Theoretical contributions to experimental http://fisica.uniandes.edu.co cosmology went to the WMAP and activities in particle physics, and Mathematical Physics by Planck collaborations for their from the design and simulation the Canadian Association of Interested applicants should fill out their personal information and submit the following documents: a) curriculum vitae including a list of publications, b) an independent and viable research plan document, and a c) teaching plan document through the following link http://fisicaconvocatoriasp.uniandes.edu.co Additionally, the applicant should provide the contact information of three references. Referees will be contacted by the Department of Physics to submit their reference letters through the online platform. CERNCOURIER The selection process will begin August 30th, 2019, giving priority to applicants that apply by that date. The destination for high-energy physics However, applications will continue to be received beyond that date until the position is filled. news and jobs For further information, please contact: Dr. Chad Leidy e-mail: cerncourier.com collaboration CMS the of benefit the for CERN, 2011 © [email protected] Head, Physics Department, Universidad de los Andes A.A. 4976, Bogotá, Colombia, Phone (57-1)-339-4949 ext. 2730

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It’s Summertime, Accelerators Photon Science Particle Physics Accelerators| Photon Science| Particle Physics | | Deutsches Elektronen-Synchrotron A Research CentreDeutsches of the Helmholtz Elektronen-Synchrotron Association time for holidays and... A Research Centre of the planning your next career step? Join CERN, a unique work environment at For our location in Hamburg we are seeking: The Faculty of Science of the University of Geneva invites the cutting edge of technology in a place like nowhere else on earth. PHOTOPHOTOScientist (f/m/diverse) CMS applications for a position as Experiment CERN currently has diverse student, graduate and professional INJECTOR FULL PROFESSOR opportunities open for application. INJECTOR• in astroparticle physics DESY,DESY Zeuthen location,• is seeking: DESY,DESY is one Zeuthen of the world’s location,leading research iscentres seeking: for photon INSTITUTE: The Department of Nuclear and Particle Postdocscience, particle (f/m) and astroparticle for the physics Photo as well Injector as accelerator Test Apply now and take part! Postdoc (f/m) for the Photo Injector Test Physics of the Science Faculty of the University of Geneva Facilityphysics. More PITZ than 2400 in Zeuthenemployees work at our two locations FacilityHamburg and PITZZeuthen in in science, Zeuthen technology and administration. offers a dynamic scientific environment with world- https://careers.cern renowned academics in the domain of particle, astroparticle The particle physics programme of DESY consists of strong and neutrino physics, as well as modern infrastructures. DESYcontributions to the LHC experiments ATLAS and CMS, the Belle-II DESYDESYExperiment is one of thein Japan world’s and leading to the research preparation centres of forfuture photon experiment science, s. The Department is actively involved in several major DESY is one of the world’s leading research centres for photon science, particleThe andexperimental astroparticle programme physics as is well enhanced as accelerator by collaboration physics. with a international experiments and has a strong link with CERN particle and astroparticle physics as well as accelerator physics. strong theory group. DESY is seeking an outstanding researcher since its foundation. Theto Photo fill a Injectorscientist Test position Facility working PITZ in Zeuthenon the CMS (near experiment. Berlin) develops The high The Photo Injector Test Facility PITZ in Zeuthen (near Berlin) develops high brightnesssuccessful electron candidate sources is forexpected Free Electron to take Lasers a leading (FELs) role like in FLASHthe ASSIGNMENT: The Department opens a full-time brightness electron sources for Free Electron Lasers (FELs) like FLASH andupgrade European program XFEL. Theof the main CMS focus experiment of the research for the program high-luminosity at PITZ is LHC. on position which includes teaching physics at bachelor, master and European XFEL. The main focus of the research program at PITZ is on further improvement of pulsed high brightness photo injectors and on deve- and postgraduate level as well as supervising master and further improvement of pulsed high brightness photo injectors and on deve- lopmentsThe position towards future high brightness CW electron sources. We also work doctoral theses. lopments towards future high brightness CW electron sources. We also work on beam• Active driven role plasma in the accelerationCMS experiment for particle and astroparticle physics. on• Engagementbeam driven plasma in the accelerationupgrade of the for particleCMS tracker and astroparticle for the HL-LHC physics. The candidate will develop original research at an The• positionlnvolvement in generic detector R&D activities international level in the field of space-borne experimental TheWork position in one of the world-leading international groups of physicists and astroparticle physics and secure external funding. He/she • • ParticipationWork in one ofin thethe world-leadingsupervision of international students and groups postdocs of physicists and •engineers for the development of photo injectors engineers for the development of photo injectors will also take on organizational and administrative duties at RequirementsPerform numerical simulations to support the accelerator R&D program • • Ph.D.Perform in Experimental numerical simulations Particleto Physics support the accelerator R&D program department, section and faculty level. •at PITZ or to optimize subcomponents of the photo injector towards at PITZ or to optimize subcomponents of the photo injector towards •applications Extensive ofknowledge high brightness and experience electron beams with forexperiments FELs and in in plasma HEP We are seeking a candidate with a proven international applications of high brightness electron beams for FELs and in plasma •acceleration Profound experience experiments in detector development, in particular silicon scientific reputation, with a wide range of skills and acceleration experiments ELI Beamlines research centre in Dolní Břežany is part of Required skills: university degree in , Developmenttracking devices of innovative concepts and techniques for the diagnostics • Development of innovative concepts and techniques for the diagnostics knowledge, including an excellent understanding of pan-European infrastructure ELI (Extreme Light Infrastructure) Engineering, Science, or related field • experience with working •of high-quality electron and laser beams • Outstandingof high-quality teamwork electron andabilities, laser beamsgood communication skills and astroparticle physics, a solid experience in data analysis representing a unique tool of support of scientific excellence in Organization of and participation in the shift operation of PITZ for acce- with scientific data and metadata • experience with setting up • knowledgeOrganization of ofEnglish and participation in the shift operation of PITZ for acce- and interpretation as well as a very good knowledge of Europe by making available its capacities to the best scientific •lerator R&D and managing databases • experience with development of APIs • lerator R&D complex satellite or space-station based detectors and their teams across the world. The aim of ELI Beamlines is to establish experience with programming in Python • good knowledge of Linux/ For further information please contact Dr. Guenter Eckerlin, +49 40 8998 2582 (guenter.eckerlin@.de) or Prof. Dr. Elisabetta Gallo, functioning, the ability to coordinate an important research the most intensive laser system in the world and to operate it Unix programming environment • proficiency in English Requirements Requirements+49-40-8998-4849Excellent university degree([email protected]). in physics or engineering with PhD group, the pedagogical aptitude, creativity and enthusiasm on a long-term basis. Due to ultra-high performances of 10 PW Desired skills: experience with machine learning for big data • Excellent university degree in physics or engineering with PhD Please•Extensive use experience our online in application beam dynamics tool to simulations submit your with complete space charge necessary for the management of students during their (1 petawatt = 1,000,000,000,000,000 watts) and concentrated processing • experience with control systems like TANGO • Extensive experience in beam dynamics simulations with space charge •dominated beams as well as in numerical methods doctoral or master studies, and the ability to initiate intensities of up to 1024 W/cm2, we can offer our users a unique applicationdominated (Motivation beams as letter, well as a inCV numerical which also methods details your research • experience in European projects and international collaborations Very deep knowledge of accelerator physics and accelerator technology source of radiation and beams of accelerated particles. The • accomplishments,Very deep knowledge a list of acceleratoryour publications, physics and and acceleratora maximum technology two communication and outreach programs for the University. We offer: the opportunity to participate in this unique scientific •Very good knowledge of English is required and knowledge of German so called beamlines will enable groundbraking research in the • pagesVery statement good knowledge on future of Englishresearch is requiredplans) and and please knowledge arrange of German for project • competitive and motivating salary • flexible working hours •is of advantage REQUIRED QUALIFICATIONS: area of physics and science dealing with materials, but also in threeis ofletters advantage of reference to be sent to the DESY human resource biomedicine and laboratory astrophysics and many other fields. • nice working environment • career growth • lunch vouchers, department ([email protected]), clearly stating your name and the • PhD in physics or equivalent. For further information please contact Dr. Mikhail Krasilnikov, +49-33762-7- ELI Beamlines is part of the of the Czech pension contribution and 5 sick days • support of leisure time Forposition further identifier. information please contact Dr. Mikhail Krasilnikov, +49-33762-7- • Strong track record in research and experience in the activities 7213 or [email protected]. Academy of Sciences, and it was open in 2015. 7213Salary or and [email protected]. benefits are commensurate with those of public service management of research groups and in teaching. Theorganisations position is limited in Germany. to 3 years. Classification is based upon qualifications • Publications in high-ranked international journals. The position is limited to 3 years. The Institute of Physics of the Czech Academy of Sciences is a Salaryand and assigned benefits duties. are commensurate Handicapped with persons those ofwill public be given service preferen organi-ce Salary and benefits are commensurate with those of public service organi- holder of the HR Excellence in Research Award. It is awarded by Applications, containing CV, cover letter, contacts of references, sationsto other in Germany. equally Classificationqualified applicants. is based uponDESY qualifications operates flexible and assigned work STARTING DATE: 01.08.2020 or upon mutual agreement sations in Germany. Classification is based upon qualifications and assigned the European Commission to institutions which put significant and any other material the candidate considers relevant, should duties.schemes. Handicapped DESY personsis an equal will beopportunity, given preference affirmative to other action equally employer qua- duties. Handicapped persons will be given preference to other equally qua- Applications including a cover letter, detailed CV and a effort into improving their HR strategy and ensuring professional be sent to Mrs. Jana Ženíšková, HR specialist (jana.zeniskova@ lifiedand applicants. encourages DESY applications operates flexible from women. work schemes. Vacant DESY positions is an at equal lified applicants. DESY operates flexible work schemes. DESY is an equal list of publications, copy of the highest degree/diploma, and ethical working conditions. eli-beams.eu, +420 - 601560322). opportunity,DESY are affirmative in general action open employer to part-timework. and encourages During applications each application from opportunity, affirmative action employer and encourages applications from research and teaching statement and a list of referees who women.procedure Vacant DESY positions will atassess DESY whether are in general the post open can to part-time-work.be filled with part- Du- Information regarding the personal data processing and access women. Vacant positions at DESY are in general open to part-time-work. Du- ringtime each employees.. application procedure DESY will assess whether the post can be can later be contacted directly by the search committee must to the personal data at the Institute of Physics of the Czech ring each application procedure DESY will assess whether the post can be filledWe with are part-time looking employees.forward to your application via our application system: be submitted before August 31st, 2019 (0:00, Geneva time) Academy of Sciences can be found on: https://www.fzu.cz/en/ filled with part-time employees. EXCLUSIVELY by clicking on the «Postuler/Apply now» Scientific Data Management Specialist processing-of-personal-data www.desy.de/onlineapplication We are looking forward to your application quoting the reference code pre- button https://jobs.unige.ch/www/wd_portal.show_ We are looking forward to your application quoting the reference code pre- (Software Engineer) ferablyDeutsches via our electronicElektronen-Synchrotron application System: DESY Online-Application ferably via our electronic application System: Online-Application job?p_web_site_id=1&p_web_page_id=41161 DeutschesHuman Resources Elektronen-Synchrotron Department | DESYCode: FHMA018/2019 Job description: Your main mission will be to implement solutions Deutsches Elektronen-Synchrotron DESY HumanNotkestraße Resources 85 Department | 22607 HamburgCode: MPO003/2017| 22607 Hamburg Germany APPLICATIONS SENT BY EMAIL SHALL NOT BE ACCEPTED. for cataloging experimental data and metadata and integrating Human Resources Department| Code: MPO003/2017 NotkestraßePhone: +49 85 4022607 8998-3392 Hamburg |Germany Phone: +49 40 8998-3392 Notkestraße 85| 22607 Hamburg| Germany| Phone: +49 40 8998-3392 In a perspective of parity, applications by women are them into PaNOSC and EOSC. You will collaborate with multiple Deadlinehttp://www.desy.de/career for applications:| 31 January| 2018 | Deadline for applications: 31 January 2018 particularly encouraged and welcome. teams at ELI as well as within PaNOSC project to bring data from www.desy.de www.desy.deDeadline for applications: 2019/07/14 their acquisition to publicly accessible web services based on FAIR Complementary information may be obtained at the Data Principles (Findable, Accessible, Interoperable, Reusable). following e-mail address: [email protected].

50 CERN COURIER JULY/AUGUST 2019

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JINR Distinguished Postdoctoral Research Fellowship Programme Сall for applications GSI Helmholtzzentrum für Schwerionenforschung in Missions Darmstadt operates one of the leading particle accelerators for The Joint Institute for Nuclear Research is seeking for outstanding science. In the next few years, the new FAIR (Facility for Anti- postdoctoral fellows and announces a call for applications for a proton and Ion Research) one of the world‘s largest research number of vacant scientific research positions. The new positions are projects, will be built in international cooperation. GSI and FAIR opened within a special Programme aimed at reinforcing the scientific offer the opportunity to work together in this international en- personnel involved in realization of the JINR top-priority projects vironment with a team of employees committed to enabling in the fields of theoretical and experimental physics of elementary world-class science. particles, relativistic heavy-ion physics, nuclear physics, condensed The department within the subproject matter physics, and radiobiology. “System Design” “SIS100/SIS18” is responsible for design and development as The Programme facilitates an opportunity for early-stage researchers well as control of the heavy ion synchrotrons in the GSI and pursuing science and engineering topics to be exposed and get FAIR facilities. For this department we are seeking as early as involved in the forefront international projects in science and technical possible an advancements at JINR Dubna. Detailed information about the Institute can be found at the JINR web site www.jinr.ru. Accelerator Physicist with Experience at Skills The successful applicant is expected to have experience and a solid Circular Accelerators (m/f/d) background in nuclear or particle physics, or in a closely related field (including a recent PhD degree). Posting ID: 6330-19.80 The successful applicant should be able to work well in an Responsibilities: international environment, such as large multinational collaborations. • Perform beam dynamics simulations aimed at design and The applicant will also be expected to take on responsibilities with the development, optimization of operation, and the provi- experiments and the analysis work and should be able to work, when needed, independently. sion of data for the control of the synchrotrons. • Plan, execute, and analyse machine experiments to The original appointment will be for up to three years. The stipend will optimize high intensity operation of the synchrotrons by be commensurate with qualifications and experience. improving the machine models used to control them. Activities and Work Context • Develop and test algorithms for software-assisted meas- The Programme will allow maximizing the benefit by exploiting at urement and feedback systems for beam-based monitor- best the research and training opportunities created by the JINR ing, adjustment, and optimization of the synchrotrons. projects. This includes a broad range of topics such as neutrino and nuclear physics, biophysics, material research (including nano), high- Qualifications and Skills: performance computing, accelerator technology, superconducting magnets, theory. • PhD in physics or a related field, considerable knowledge in accelerator physics and years of demonstrated Closing Date experience with simulation and operation of circular The review of applications will begin on 01.09.2019 and will continue careers accelerators. until the opportunities are filled. • Ideally, experience with ion optical simulation of non-lin- Career opportunities for those with a background Please circulate this information to any colleagues you may feel could ear effects, especially slow extraction, and practical be interested. experience with optimization of space charge dominated in physics and related subjects Further details for applications are made via the employment platforms circular accelerators with respect to beam loss. of JINR Laboratories for respective vacancies: • Structured work habit, excellent team working, business A bumper-sized book with helpful careers advice, real-life case studies, fluent English and the willingness to learn German. Vacant positions within the Programme as well as an extensive employer directory powered by brightrecruits NICA relativistic heavy-ion physics – 2 positions The position is initially limited to a duration of 5 years. GSI http://lhe.jinr.ru supports the vocational development of women. Therefore, Download the free Physics World app today! Accelerator physics and technologies – 3 positions women are especially encouraged to apply for the position. http://lhe.jinr.ru Handicapped persons will be preferentially considered when equally qualified. Spin physics with polarized ion beams @ NICA – 1 position http://lhe.jinr.ru Please send your application stating the posting-ID at the latest until 9 August 2019 to: Radiobiology – 1 position http://lrb.jinr.ru GSI Helmholtzzentrum für Schwerionenforschung GmbH Abteilung Personal Neutron physics – 3 positions Read online at physicsworld.com/careers http://flnph.jinr.ru Planckstraße 1 64291 Darmstadt Neutrino physics – 3 positions Germany http://dlnp.jinr.ru or by email to: [email protected]

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JOURNAL Chinese Physics C IMPACT FACTOR High Energy and Nuclear Physics 5.861 PEOPLE

Covering theory, experiment and application research OBITUARIES ofIncreasing particle, nuclear and high-energy physics the impact of your research

ISSN 1674-1137 Why should you publish in Chinese Chinese83% of Physicsours and C our partner’sPhysics titles C (CPC)? High Energy and Nuclear Physics Olga BOrisOvna igOnkina 1973–2019 have seen an increase in• their Increase 2018 citations for your Journal Impact Factors* research – CPC received 96,665 A Series Journal of the Chinese Physical Society Distributed by IOP Publishing downloads in 2018 iopscience.org/cpc cpc.ihep.ac.cn VolumeVisit 43 January 2019 iopscience.org/impact-factors Number 1 • Increase the impact of your A talent and a love for physics

research – CPC’s journal impact CERN to read the latest articles published in Nikhef particle physicist and sample of B decays in ATLAS for the factor has increased by 78% prominent member of the ATLAS fi n a l y e a r o f R u n 2. S h e w a s w orking IOP journals Fast publication times for your • experiment at CERN, Olga Igonkina, on preparations for an RK measure- work – from submission to first 3.516 2.799 1.193 4.128 passed away on 19 May in Amster- ment until her very last days. decision, CPC takes only 24 days dam at the age of 45. Besides being a talented scientist,

Chinese PhysiCal soCiety Olya, as she was known to most of Olya was a dedicated teacher. She us, was born in 1973 in Moscow. Her supervised an impressive number of Editor-in-Chief father was an engineer, her mother PhD students and was very success- Yifang Wang (王贻芳) a biological scientist. At age 14 she ful in obtaining research grants. Institute of High Energy Physics, CAS, Beijing, China went to a special school for children She was also very active in outreach talented in mathematics and in 1991 activities, with masterclasses and started her studies in physics at the open days at Nikhef, and in com- To find out more about the journal and how to submit your Moscow Institute for Physics and munity building at ATLAS. Recently research, please visit iopscience.org/cpc *2018 Journal Impact Factor, Journal Citation Reports Technology. Two years later Olya she organised the 15th International (Web of Science Group, 2019) 3.534 3.487 5.861 5.524 moved to the ITEP institute to spe- Workshop on Tau Lepton Physics cialise in particle physics, working conference in . at the ARGUS experiment and later Olya was a passionate physi- the HERA-B experiment at DESY. cist who was bursting with ideas. Olya wrote her dissertation about Among several tributes from her J/ψ production in HERA-B, with colleagues, Olya was described as a Mikhail Danilov as her supervisor. Olya was an expert in tau physics. future experiment leader. She had a In 2002 she moved to BaBar at SLAC memorably strong work ethos, and as a postdoc with the University of and enthusiasm, in particular as the l e p t o n fl a v o u r v i ol a t i o n, i n p a r t icu- until the very last moment refused JOURNAL Oregon in the group of Jim Brau, trigger-menu coordinator during lar in tau decays. Intrigued by the to let her illness affect her work. IMPACT FACTOR where she worked on searches for the startup of the LHC, and later on hints of lepton-flavour violation She was always cheerful and always Chinese Physics C l e p t o n-fl a v o u r-v i ol a t i n g t a u d e c a ys physics with tau leptons. She began in B decays reported by the LHCb positive. Her attitude to work and 5.861 and became convener of the BaBar her appointment at Nikhef in 2008 experiment and B factories, and life will remain a source of inspi- tau working group. In 2006 she and in 2015 became a professor at always on the lookout for a niche ration to many of us. High Energy and Nuclear Physics moved to CERN to spearhead Ore- Radboud University in Nijmegen. in a large collaboration, in 2018 Olya Olya leaves behind her husband, gon’s new ATLAS group. Her work For her efforts on the ATLAS m o v e d s o m e o f h e r e ffor t s f r o m t au Wouter Hulsbergen of Nikhef, and

ISSN 1674-1137 in ATLAS concentrated on the trigger, Olya was given an ATLAS to B physics. She took responsibil- two children. Covering theory, experiment and application research trigger, where she contributed to outstanding achievement award in ity for the B-hadron triggers with Chinese Physics C of particle, nuclear and high-energy physics many activities with great ideas 2018. Physics-wise, her passion was the aim of collecting an even larger Her colleagues and friends. High Energy and Nuclear Physics Why should you publish in Chinese Physics C (CPC)? Dieter renker 1944–2019 • Increase citations for your research – CPC received 96,665 downloads in 2018 A Series Journal of the Chinese Physical Society Distributed by IOP Publishing A curious physicist with detector expertise iopscience.org/cpc cpc.ihep.ac.cn • Increase the impact of your research – CPC’s journal impact factor has Volume 43 January 2019 Number 1

increased by 78% NDIP Dieter Renker, who made some key the end of 2009. Renker’s pioneering measurements • Fast publication times for your work – from submission to first decision, CPC contributions to the design and At SIN/PSI he participated in led to lead-tungstate crystals being takes only 24 days construction of the CMS exper- many experiments, providing adopted by the CMS calorimeter. iment at the LHC, passed away excellent technical support, as Editor-in-Chief on 16 March after a short illness. well as designing new beamlines for operation at the LHC, have a Yifang Wang (王贻芳), Institute of High Energy Physics, CAS, Beijing, China Dieter was born in Bavaria and at the accelerator there. His tech- relatively small scintillation-light studied physics in Munich and nical aptitude in due course turned yield. Dieter contributed the key Berlin. He obtained his PhD from to detector development, which measurements which showed To find out more about the journal and how to submit your the Ludwig Maximilian University led to his greatest achievement. that avalanche photodiodes research, please visit iopscience.org/cpc in Munich, based on experiments In the early days of CMS there (APDs), with their key properties Chinese PhysiCal soCiety performed at SIN, now the Paul were various ideas for the design of internal gain and insensitivity Scherrer Institute (PSI), in Villi- of the electromagnetic calorimeter. to shower leakage, could be used gen, Switzerland. In 1982 he joined Among these was the use of lead to read out the crystals. This led SIN as a staff physicist, where he tungstate crystals, which although to lead-tungstate crystals being s remained until his retirement at having many suitable properties adopted by CMS for the design of

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PEOPLE OBITUARIES PEOPLE OBITUARIES

the caorimeter. Not ony did they of many years by Hamamatsu be improved, and the fi nal choice requirements of CMS. Until now a nton oed 1933–2018 provide superb energy resoution Photonics (apan), but under the was made very cose to the deadine there has been no recorded faiure for eectrons and photons, enabing cose guidance of Dieter. Neary for commencing construction of of any of the 122,000 APDs instaed key discoveries such as the Higgs 100 different APD prototypes the caorimeter. A compex muti- in CMS. An inspirational inventor boson in 2012, but they aso ena- were tested before the technoogy step screening process invoving Later, Dieter turned his atten- bed a more compact detector with w a s de eme d fi t to b e use d i n C M S. gamma irradiation and annea- tion to Geiger-mode APDs, which Anton Oed, a passionate inventor Grenoble in 1979, and set about Artechnique/ILL a l s o u s e d t o d e t e c t X-r a y s o n E S A’s signifi cantly reduced overall cost. The size, capacitance, speed and, ing aso needed to be deveoped are now widey used in partice and a source of inspiration for many d e v e l o pi n g t h e d e t e c t or o f t h e “C o s i INTEGRAL telescope. The deveopment of the fina above a, radiation toerance were to ensure that the APDs instaed and astropartice physics, as we of us today, passed away on 30 Sep- Fan Tutte” spectrometer to measure In 1997 Anton received the R W APD was carried out over a period the key parameters that needed to met the demanding reiabiity as in PET scanners. Together tember 2018. His introduction of the mass, charge and kinetic energy Pohl medal from the Deutsche with researchers at ETH urich, micro-strip gas chambers (MSGCs) of fission fragments. The results Physikalische Gesellschaft for the he started the deveopment of at the Institut Laue-Langevin (ILL) obtained with this detector were so invention of the MSGC. To honour the fi rst camera based on these in 1988 was a decisive breakthrough precise that it has been taken as a h i s m e m or y, t h e I L L h a s e s t a bl i s h e d novel photo sensors for Cher- in the field of radiation detectors. r e fe r e n c e for s e v e r a l nu c l e a r i n s t r u- a prize promoting his innova- enkov teescopes to measure It demonstrated a significant gain ments in other institutes. Anton tive spirit and the ability to solve very high-energy gamma rays in spatial resolution and counting later started developing the MSGC technical challenges in the field of from astrophysica sources. This rate, and the invention immedi- technique to upgrade detectors of micro-pattern gas detectors. c a me r a w a s i n s t a l le d at t he FAC T ately stimulated the development neutron diffractometers. Several Memories of the technology’s teescope, ocated in La Pama, o f a n e w c l a s s o f m i c r o -p a t t e r n g a s ILL i n s t r u me nt s a re now e qu ipp e d development and of Anton’s per- Spain, where the HEGRA experi- detectors (MPGDs). with MSGCs that have been in oper- sonality were shared during a ment had aso been operated with Anton was born 1933 in Ulm, ation for more than 10 years. special session at the MPGD 2019 Germany, and studied physics at The development of MSGCs for conference held in La Rochelle from the University of Tübingen. For his high-energy physics started at the 5–10 May. He has always been of d i pl o m a t h e s i s o n “T h e d o u bl e r e s o - beginning of the 1990s. Encour- great inspiration to many of the nance spectrum of 23Na”, he received aging results were obtained by collaborators working with him. the prize of the Faculty of Mathe- the RD28 collaboration at CERN We will remember him as a very mat ics a nd Nat ur a l Sc iences of t he but t he relat ive fragilit y of MSGCs Anton Oed with a micro-strip plate. friendly and enthusiastic person, University of Tübingen. In his doc- under harsh irradiation conditions a s w e l l a s for h i s k i n d n e s s t o w a r d s toral thesis, again in atomic physics, motivated the development of new have become very successful and everybody. he studied the double-quanta decay detectors with improved robust- are currently being implemented of t he hydrogen 2S level. ness. Among these, Micromegas in various upgrades to the LHC Bruno Guérard Anton arrived at the ILL in a n d g a s e l e c t r o n m u l t i pl i e r s (GE M s) experiments. MSGC detectors are Institut Laue-Langevin.

Jacques soffer 1940–2019

Dieters active participation. The Compact FACT telescope has now been Prolific theorist and polarisation pioneer operating successfuy for more than seven years, without any Ja c q u e s S o ffe r, a pr ol i fic t h e or i s t a nd Box/Hop P with energy of the proton–pro- inspired by his work and carried out Photomultipliers sensor-reated probems. phenomenologist with nearly 300 ton cross-section. This prediction with his guidance. Along his career, After his retirement Dieter articles in journals or conference still holds when compared with Jacques organised or co-organised returned to his spiritua home, proceedings to his name, was born experimental data after a 100-fold several workshops and conferences for Scintillation Munich, where he continued his i n 1940 i n M a r s e i l l e. D u r i n g t h e w a r, increase in collision energy – up on spin physics, and in more recent work at t he Tec hnical Universit y. he and his family were sheltered to and including LHC energies. In years was often giving the sum- Applications Dieter was a curious physicist in a farm in the Alps. Afterwards, 1999 Ja c q u e s c o nt r i b ut e d t o a p a p e r mar y tal k. with an exceptiona taent for Jacques came back to Marseille, showing how to make an absolute Throughout his pioneering work nove detector concepts. He pur- studied there, and obtained his doc- measurement of the degree of i n p a r t i c l e p h y s i c s, Ja c q u e s a l w a y s sued new ideas with a strong focus t or a l d e g r e e u n d e r t h e s u p e r v i s i o n polarisation of a proton beam – got to the central issues very on achieving his goas. He had a of A Visconti. He spent most of his which was essential to the success q u i c k l y, g u i d e d b y a n u n c a n n y fe e l- Introducing our compact range of end very open mind, and was wiing career at the Centre de Physique o f t h e Br o o k h a v e n s pi n pr o g r a m m e. ing for the new physics that roused to advise and assist coeagues Théorique in Marseille, serving In recent years, Jacques showed the amazement and admiration of window photomultipliers with blue-green sensitive with great patience and good as director from 1986 to 1993. He how positivity sets bounds on his collaborators. His colleagues bialkali photocathode and 10 high gain, high stability, SbCs humour. In his free time his inter- enjoyed sabbaticals at Maryland, spin observables, with important and collaborators, and especially ests incuded cassica music and Cambridge, CERN, the Weizmann applications to the extraction and his thesis students, benefited from dynodes of linear focused design for good linearity and timing. cooking as we as searching the Institute and Lausanne University, determination of the polarised h i s a d v i c e a n d h i s br o a d k n o w l e d g e woods for unusua edibe mush- and after his retirement he became parton structure functions and to of theory tools and experimental The compact nature of these photomultiplier tubes make these designs ideal for rooms. Many colleagues and adjunct-professor at Temple Uni- low-energy hadron–hadron scat- facts. They unanimously praised visitors have fond memories of versity in the US. tering. His various achievements his warm friendship and hospi- use in scintillation applications. invitations to his home, embe- Jacques played a big pa r t i n per- c u l m i n a t e d i n t h r e e m aj or r e v i e w s tality, his sense of humour and his lished w it h fi ne cook ing. suading the elementary particle Soffer showed how to extract physics in Physics Reports. widespread interests in the arts, His sudden iness was a shock community of the importance of from polarised proton beams. Jacques always cooperated literature and technology. to many. Dieter eaves behind his polarisation-type measurements, closely and fruitfully with exper- Jacques is survived by his wife, partner, Ulrike. which provide a probe of dynami- the community for predicting, imentalists. Entire programmes, Danielle, their three children and cal theories far sharper than tests together with Claude Bourrely suc h a s t he p ol a r i s e d proton–pro- nine grandchildren. www.et-enterprises.com Visit us at www.et-enterprises.com uenin ngra Paul cherrer i n v ol v i n g j u s t d i ffe r e nt i a l a n d t o t al and Tai Wu in 1984, the dramatic t o n c ol l i s io n s a t Br o o k h a v e n’s R e l- Institute and friends of ieer. cross-sections. He is renowned in phenomenology of the growth ativistic Heav y-Ion Collider, were His friends and colleagues.

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Notes and observations from the high-energy physics community Designs on Higgs at 90 From the archive: July/August 1976 Tbilisi under the spell of Charm As part of a series of celebrations to mark ’ 90th birthday, About 800 physicists from many the University of Edinburgh launched a competition for primary- parts of the world attended the school children in Scotland to design a birthday card. Hundreds of entries were received, and the winning cards in each age group 18th International Conference on High Energy Physics, one of the (rang ing from age 4–12) were presented to Higgs at an official bir t hday The four quarks— Up, Down, Strange, dinner on 29 May. While these and the runners-up designs are indeed biennial Rochester Conferences, Charm — sketched by rapporteur inspired (see below), we can’t help but feel that the students missed in July 1976 in Tbilisi, the capital A de Rujula. a t ric k by not riffing on t he famous pre-Higgs discover y “blue- of the Georgian Soviet Socialist band” plot, in which a global χ2 fit of elect rowea k parameters had a Republic. With events found at CERN, Fermilab, DESY and SPEAR, minimum at a Higgs mass of around 90 GeV/c 2. the consensus clearly was that particles bearing the new quantum number, charm, have been found. And the charm was not ‘hidden’, as in the J/ψ and ψ′, but unashamedly ‘naked’, with characteristic D Cheskin decays involving leptons and strange particles and ‘exotic’ relationships between electric charge and strangeness. The discovery of charm confirms one of the more striking aspects of a theory developed over several years by many authors. One version, sometimes called the ‘standard model’, is based on the work of Weinberg and Salam and of Glashow, lliopoulos and Maiani. The theory is proving powerful in predicting phenomena such as neutral currents, and the understanding brought about by its unification of electric and weak forces has been compared to that achieved by Maxwell in unifying electricity and magnetism.  Compiled from text on p252 of CERN Courier July/August 1976. Compiler’s note Scientific American (17 June) about With the second generation of quarks complete, the Media corner the and search was on for a third pair, predicted by Kobayashi whether theory or experiment and Maskawa in 1973 and named “top” and “bottom” “We will look at this possibility and should come first. by Haim Hartari. Lederman’s team at Fermilab found will continue to maintain contacts the bottom in 1977, but it took another 18 years before with you on that matter.” 2 “Our new buildings do have the 173 GeV/c top was finally discovered in 1995, Russian prime minister Dmitry photovoltaics on the roofs and a also at Fermilab, 86,500 times heavier than the lightest Medvedev, who visited CERN on lot of insulation, but if I have one . 10 June, quoted by Russian news or two million Euros to spend, agency TASS on the topic of Russia

obviously it is better to inject it into D Ricci/2019-070-1 becoming a CERN Member State. the 90% of energy consumption [used by the machines, detectors “The discovery doesn’t radically and computing] rather than the change our perspective on physics 10% [the buildings use].” yet because it matches theoretical Frédérick Bordry, CERN director of predictions – and it certainly isn’t a accelerators and technology, Cabling in warp engine.” discussing the environmental the SPS Theorist Chanda Prescod-Weinstein credentials of large laboratories in tunnel. on the discovery of CP violation in the June issue of Physics World. charm mesons and its connection to Star Trek propulsion systems “Particle accelerators can be seen as (New Scientist 15 June). analogues to Anton Chekhov’s gun: if there’s one shown in the first act, Total length of optical fibres “It is not intended to be used as a it must be fired in the third.” and copper cables that will be verification tool for a specific theory From a review of Particle Panic! installed or removed during the but as a means of paving multiple How Popular Media and Popularized 1996 km current two-year shutdown of experimental paths for the future.” Science Feed Public Fears of Particle CERN’s accelerator complex Grigoris Panoutsopoulos and Accelerator Experiments (Springer Frank Zimmermann writing in 2019) in Cosmos magazine, 15 June.

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