DOCSLIB.ORG

'Vague, but Exciting'

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

I n t e r n at I o n a l Jo u r n a l o f HI g H -en e r g y PH y s I c s CERN COURIERV o l u m e 49 nu m b e r 4 ma y 2009 ‘Vague, but exciting’ ACCELERATORS COSMIC RAYS COLLABORATIONS FFAGs enter the era of PAMELA finds a ATLAS makes a smooth applications p5 positron excess p12 changeover at the top p31 CCMay09Cover.indd 1 14/4/09 09:44:43 CONTENTS Covering current developments in high- energy physics and related fields worldwide CERN Courier is distributed to member-state governments, institutes and laboratories affiliated with CERN, and to their personnel. It is published monthly, except for January and August. The views expressed are not necessarily those of the CERN management. Editor Christine Sutton Editorial assistant Carolyn Lee CERN CERN, 1211 Geneva 23, Switzerland E-mail [email protected] Fax +41 (0) 22 785 0247 Web cerncourier.com Advisory board James Gillies, Rolf Landua and Maximilian Metzger COURIERo l u m e u m b e r a y Laboratory correspondents: V 49 N 4 m 2009 Argonne National Laboratory (US) Cosmas Zachos Brookhaven National Laboratory (US) P Yamin Cornell University (US) D G Cassel DESY Laboratory (Germany) Ilka Flegel, Ute Wilhelmsen EMFCSC (Italy) Anna Cavallini Enrico Fermi Centre (Italy) Guido Piragino Fermi National Accelerator Laboratory (US) Judy Jackson Forschungszentrum Jülich (Germany) Markus Buescher GSI Darmstadt (Germany) I Peter IHEP, Beijing (China) Tongzhou Xu IHEP, Serpukhov (Russia) Yu Ryabov INFN (Italy) Romeo Bassoli Jefferson Laboratory (US) Steven Corneliussen JINR Dubna (Russia) B Starchenko KEK National Laboratory (Japan) Youhei Morita Lawrence Berkeley Laboratory (US) Spencer Klein Seeing beam once again p6 Dirac was right about antimatter p15 A new side to Peter Higgs p36 Los Alamos National Laboratory (US) C Hoffmann NIKHEF Laboratory (Netherlands) Paul de Jong Novosibirsk Institute (Russia) S Eidelman News 5 NCSL (US) Geoff Koch Orsay Laboratory (France) Anne-Marie Lutz FFAGs enter the applications era. Laser-pulse blasts set antiparticle PSI Laboratory (Switzerland) P-R Kettle production record. First sector is closer to cool down ... while the injection Saclay Laboratory (France) Elisabeth Locci Science and Technology Facilities Council (UK) Peter Barratt chain sees beam again. ALICE prepares for jet measurements. Editor’s TRIUMF Laboratory (Canada) Marcello Pavan note. NSCL researchers constrain nuclear symmetry energy at low density. Produced for CERN by IOP Publishing Ltd IOP Publishing Ltd, Dirac House, Temple Back, Sciencewatch 11 Bristol BS1 6BE, UK Tel +44 (0)117 929 7481 Astrowatch 12 Publisher Jo Nicholas CERN Courier Archive 13 Art director Andrew Giaquinto Production editor Jesse Karjalainen Technical illustrator Alison Tovey Features Advertising manager Ed Jost Why antihydrogen and antimatter are different 15 Recruitment advertisement manager Moo Ali Advertisement production Katie Graham As Dirac realized, there’s more to antimatter than antihydrogen. Marketing & Circulation Anastasia Ireland New Zealand meeting looks at dark matter 19 Advertising Tel +44 (0)117 930 1026 (for UK/Europe display advertising), The Dark 2009 conference took place in Christchurch earlier this year. +1 215 627 0880 (for North American display advertising), or +44 (0)117 930 1027 (for recruitment advertising); Study group considers how to preserve data 21 E-mail: [email protected]; fax +44 (0)117 930 1178 How can high-energy physics data best be saved for the future? General distribution Courrier Adressage, CERN, 1211 Geneva 23, Switzerland. E-mail: [email protected] Happy 20th birthday, World Wide Web 24 In certain countries, to request copies or to make address changes, Something happened at CERN in 1989 that changed the world forever. contact: China Keqing Ma, Library, Institute of High Energy Physics, PO Box 918, Beijing 100049, People’s Republic of China. Nara workshop looks at heavy quarkonia 27 E-mail: [email protected] A report from the latest meeting of the Quarkonium Working Group. Germany Veronika Werschner, DESY, Notkestr. 85, 22607 Hamburg, Germany. E-mail: [email protected] 31 Italy Loredana Rum or Anna Pennacchietti, INFN, Casella Postale ATLAS makes a smooth changeover at the top 56, 00044 Frascati, Rome, Italy. E-mail: [email protected] Peter Jenni and Fabiola Gianotti reflect on the role of ATLAS spokesperson. UK Mark Wells, Science and Technology Facilities Council, Polaris House, North Star Avenue, Swindon, Wiltshire SN2 1SZ. Faces and Places 34 E-mail: [email protected] US/Canada Published by Cern Courier, 6N246 Willow Drive, St Charles, IL 60175, US. Periodical postage paid in St Charles, IL, Recruitment 40 US. Fax 630 377 1569. E-mail: [email protected] POSTMASTER: send address changes to: Creative Mailing Services, Bookshelf 43 PO Box 1147, St Charles, IL 60174, US Viewpoint 46 Published by European Organization for Nuclear Research, CERN, 1211 Geneva 23, Switzerland. Tel +41 (0) 22 767 61 11 Telefax +41 (0) 22 767 65 55 Printed by Warners (Midlands) plc, Bourne, Lincolnshire, UK © 2009 CERN ISSN 0304-288X Cover: In March 1989 Tim Berners-Lee, a physicist at CERN, handed a document to his supervisor Mike Sendall, titled “Information Management: a Proposal”. “Vague, but exciting”, were the words that Sendall wrote on the proposal, allowing Berners-Lee to continue with the project. This low-key beginning to the phenomenon that became the World Wide Web was celebrated at CERN in March (p24). CERN Courier May 2009 3 CCMay09Contents.indd 3 14/4/09 09:24:44 WIENER Magnet Power Supply Systems In addition to the standard power supplies PL (low voltage, high currents) and Mpod (High and low voltages, multichannel), W-Ie-Ne-R presents now PG 501 a 1,8 kW programmable bipolar current source for magnets in 3 U format. Main features Remote and local controls, ability to ramp from full negative current to full positive current going through zero without requiring operator intervention for changing output polarity once the ramp is initiated. Stable operation at zero current output. Adjustable slew rate, no overshot Magnet Load Range Resistance: 80 mȍ - 100ȍ Inductance: 0 - 2H Output Voltage: +/- 50 / 75 /100V (compliance voltage) Current: +/- 33 / 24 / 20A (16 bit setting resolution) Current cascading by parallel operation of several units Regulation and stability < 100 PPM (on full scale) Ripple and noise < 10mVpp Slew rate (user adj.) ~1-50A/s Control resolution 16 bit Interlocks Internal Protection Control interfaces Monitoring Over current Local Communication failure AC input under voltage Ethernet Control power OK Over voltage USB Regulation failure / status RS232 / 485 alternatively Current / Voltage / Temperature Over temperature / cooling fault Set points read back Ground fault detection Interlock fault status Summation fault Since 1959: www.wiener-d.com Plein & Baus GmbH, Muellersbaum 20, 51399 Burscheid, Germany Phone: (+49) 2174 6780, Fax: (+49) 2174 678 55 Bleed full page template.indt 1 7/4/09 10:59:48 NEWS ACCELERATORS FFAGs enter the applications era After a series of preliminary tests held on the FFAG accelerator provides a high-energy 26–27 February the Research Reactor proton beam to a heavy-metal target in the Institute of Kyoto University (KURRI) received KUCA to produce spallation neutrons, which a national licence to conduct experiments in turn drive fission chain reactions in the for an accelerator-driven subcritical reactor KUCA-A Core. (ADSR) using the Kyoto University Critical The aim is to examine the feasibility of Assembly (KUCA). The first ADSR experiment an ADSR and to lay the foundations for its began on 4 March using a newly developed development. The fact that the reactor is fixed-field alternating-gradient (FFAG) proton driven slightly below criticality makes this accelerator connected to the KUCA. This system intrinsically safe: as soon as the marks the first use of an FFAG accelerator The proton FFAG accelerator. (Courtesy KURRI.) external neutron supply is stopped, fission built for a specific application rather than as a chain reactions cease. ADSRs may also be prototype, and it heralds the start of a new era goal, was initiated in 2002 under a contract useful for the transmutation of long-lived (CERN Courier September 2008 p21). with the Ministry of Education, Culture, Sports, transuranic elements into shorter-lived or The Development of an Accelerator Driven Science and Technology (MEXT) as part of the stable elements. They therefore have the Subcritical Reactor using an FFAG Proton Technology Development Project for Innovative potential to be used as energy amplifiers, Accelerator project, which is now reaching its Nuclear Energy Systems. In the experiment neutron sources and transmutation systems. Laser-pulse blasts set antiparticle production record The latest record for antiparticle density created in the laboratory has not come from an accelerator facility but from the Lawrence Livermore National Laboratory’s Jupiter laser facility. Hui Chen and colleagues blasted picosecond laser pulses carrying 1020 Wc m –2 from the Titan laser onto gold targets some Hui Chen sets up targets for the antimatter experiment at the Jupiter laser facility. (Courtesy LLNL.) 1 mm thick. Part of each laser pulse created a plasma and part drove the plasma’s electrons In addition to being intrinsically interesting and pair-creation from high-energy photons at into the gold. The gold nuclei then slowed this work could aid better understanding of accelerators. down the electrons, producing photons that astrophysical
Recommended publications
  • CERN Courier–Digital Edition

    CERN Courier–Digital Edition

    CERNMarch/April 2021 cerncourier.com COURIERReporting on international high-energy physics WELCOME CERN Courier – digital edition Welcome to the digital edition of the March/April 2021 issue of CERN Courier. Hadron colliders have contributed to a golden era of discovery in high-energy physics, hosting experiments that have enabled physicists to unearth the cornerstones of the Standard Model. This success story began 50 years ago with CERN’s Intersecting Storage Rings (featured on the cover of this issue) and culminated in the Large Hadron Collider (p38) – which has spawned thousands of papers in its first 10 years of operations alone (p47). It also bodes well for a potential future circular collider at CERN operating at a centre-of-mass energy of at least 100 TeV, a feasibility study for which is now in full swing. Even hadron colliders have their limits, however. To explore possible new physics at the highest energy scales, physicists are mounting a series of experiments to search for very weakly interacting “slim” particles that arise from extensions in the Standard Model (p25). Also celebrating a golden anniversary this year is the Institute for Nuclear Research in Moscow (p33), while, elsewhere in this issue: quantum sensors HADRON COLLIDERS target gravitational waves (p10); X-rays go behind the scenes of supernova 50 years of discovery 1987A (p12); a high-performance computing collaboration forms to handle the big-physics data onslaught (p22); Steven Weinberg talks about his latest work (p51); and much more. To sign up to the new-issue alert, please visit: http://comms.iop.org/k/iop/cerncourier To subscribe to the magazine, please visit: https://cerncourier.com/p/about-cern-courier EDITOR: MATTHEW CHALMERS, CERN DIGITAL EDITION CREATED BY IOP PUBLISHING ATLAS spots rare Higgs decay Weinberg on effective field theory Hunting for WISPs CCMarApr21_Cover_v1.indd 1 12/02/2021 09:24 CERNCOURIER www.
  • Subnuclear Physics: Past, Present and Future

    Subnuclear Physics: Past, Present and Future

    Subnuclear Physics: Past, Present and Future International Symposium 30 October - 2 November 2011 – The purpose of the Symposium is to discuss the origin, the status and the future of the new frontier of Physics, the Subnuclear World, whose first two hints were discovered in the middle of the last century: the so-called “Strange Particles” and the “Resonance #++”. It took more than two decades to understand the real meaning of these two great discoveries: the existence of the Subnuclear World with regularities, spontaneously plus directly broken Symmetries, and totally unexpected phenomena including the existence of a new fundamental force of Nature, called Quantum ChromoDynamics. In order to reach this new frontier of our knowledge, new Laboratories were established all over the world, in Europe, in USA and in the former Soviet Union, with thousands of physicists, engineers and specialists in the most advanced technologies, engaged in the implementation of new experiments of ever increasing complexity. At present the most advanced Laboratory in the world is CERN where experiments are being performed with the Large Hadron Collider (LHC), the most powerful collider in the world, which is able to reach the highest energies possible in this satellite of the Sun, called Earth. Understanding the laws governing the Space-time intervals in the range of 10-17 cm and 10-23 sec will allow our form of living matter endowed with Reason to open new horizons in our knowledge. Antonino Zichichi Participants Prof. Werner Arber H.E. Msgr. Marcelo Sánchez Sorondo Prof. Guido Altarelli Prof. Ignatios Antoniadis Prof. Robert Aymar Prof. Rinaldo Baldini Ferroli Prof.
  • CURRICULUM VITAE – Paul D. Grannis April 6, 2021 DATE of BIRTH: June 26, 1938 EDUCATION

    CURRICULUM VITAE – Paul D. Grannis April 6, 2021 DATE of BIRTH: June 26, 1938 EDUCATION

    CURRICULUM VITAE { Paul D. Grannis July 15, 2021 EDUCATION: B. Eng. Phys., with Distinction, Cornell University (1961) Ph.D. University of California, Berkeley (1965) Thesis: Measurement of the Polarization Parameter in Proton-Proton Scattering from 1.7 to 6.1 BeV Advisor, Owen Chamberlain EMPLOYMENT: Research Professor of Physics, State Univ. of New York at Stony Brook, 2007 { Distinguished Professor Emeritus, State Univ. of New York at Stony Brook, 2007 { Chair, Department of Physics and Astronomy, Stony Brook, 2002 { 2005 Distinguished Professor of Physics, State Univ. of New York at Stony Brook, 1997 { 2006 Professor of Physics, Stony Brook, 1975 { 1997 Associate Professor of Physics, Stony Brook, 1969 { 1975 Assistant Professor of Physics, Stony Brook, 1966 { 1969 Research Associate, Lawrence Radiation Laboratory, 1965 { 1966 1 AWARDS: Danforth Foundation Fellow, 1961 { 1965 Alfred P. Sloan Foundation Fellow, 1969 { 1971 Fellow, American Physical Society Fellow, American Association for the Advancement of Science Exceptional Teaching Award, Stony Brook, 1992 Exceptional Service Award, U.S. Department of Energy, 1997 John S. Guggenheim Fellowship, 2000 { 2001 American Physical Society W.K.H. Panofsky Prize, 2001 Honorary Doctor of Science, Ohio University, 2009 W. V. Houston Memorial Lectureship, Rice University 2012 Foreign member, Russian Academy of Science, 2016 Co-winner with the members of the DØ Collaboration, European Physical Society High Energy Particle Physics Prize, 2019 2 OTHER ACTIVITIES: Visiting Scientist, Rutherford
  • CERN Inaugurates LHC Cyrogenics

    CERN Inaugurates LHC Cyrogenics

    FACES AND PLACES SYMPOSIUM CERN inaugurates LHC cyrogenics Inauguration and ribbon-cutting ceremony of LHC cryogenics by CERN officials: from left, Giorgio Passardi, leader of cryogenics for experiments group; Philippe Lebrun, head of the accelerator Members of the CERN cryogenic groups in front of the Globe of technology department; Giorgio Brianti, founder of the LHC Science and Innovation, where the symposium took place. (Globe project; Lyn Evans, LHC project leader and Laurent Tavian, leader conception T Buchi, Charpente Concept and H Dessimoz, Group H.) of the cryogenics for accelerators group. The beginning of June saw the start of a coils operating at 1.9 K. Besides enhancing Tennessee. Although the commissioning new phase at the LHC project, with the the performance of the niobium-titanium work is far from finished, the cyrogenics inauguration of LHC cryogenics. This was superconductor, this temperature regime groups at CERN felt that after 10 years of marked with a symposium in the Globe makes use of the excellent heat-transfer construction it was now a good time to of Science and Innovation attended by properties of helium in its superfluid state. celebrate, organizing the Symposium for the 178 representatives of the research The design for the LHC cryogenics had to Inauguration of LHC Cryogenics that took institutes involved and industrial partners. incorporate both newly ordered and reused place on 31 May-1 June at CERN's Globe of It also coincided with the stable low- refrigeration plant from LEP operating Science and Innovation. After an inaugural temperature operation of the cryogenic plant at 4.5 K – together with a second stage address by CERN’s director-general, for sector 7–8, the first sector to be cooled operating at 1.9 K – in a system that could Robert Aymar, the programme included down (CERN Courier May 2007 p5).
  • CERN Courier – Digital Edition Welcome to the Digital Edition of the November 2018 Issue of CERN Courier

    CERN Courier – Digital Edition Welcome to the Digital Edition of the November 2018 Issue of CERN Courier

    I NTERNATIONAL J OURNAL OF H IGH -E NERGY P HYSICS CERNCOURIER WELCOME V OLUME 5 8 N UMBER 9 N OVEMBER 2 0 1 8 CERN Courier – digital edition Welcome to the digital edition of the November 2018 issue of CERN Courier. Physics through Explaining the strong interaction was one of the great challenges facing theoretical physicists in the 1960s. Though the correct solution, quantum photography chromodynamics, would not turn up until early the next decade, previous attempts had at least two major unintended consequences. One is electroweak theory, elucidated by Steven Weinberg in 1967 when he realised that the massless rho meson of his proposed SU(2)xSU(2) gauge theory was the photon of electromagnetism. Another, unleashed in July 1968 by Gabriele Veneziano, is string theory. Veneziano, a 26-year-old visitor in the CERN theory division at the time, was trying “hopelessly” to copy the successful model of quantum electrodynamics to the strong force when he came across the idea – via a formula called the Euler beta function – that hadrons could be described in terms of strings. Though not immediately appreciated, his 1968 paper marked the beginning of string theory, which, as Veneziano describes 50 years later, continues to beguile physicists. This issue of CERN Courier also explores an equally beguiling idea, quantum computing, in addition to a PET scanner for clinical and fundamental-physics applications, the internationally renowned Beamline for Schools competition, and the growing links between high-power lasers (the subject of the 2018 Nobel Prize in Physics) and particle physics. To sign up to the new-issue alert, please visit: cerncourier.com/cws/sign-up.
  • Why Antihydrogen and Antimatter Are Different As Paul Dirac Realized, the Existence of Antihydrogen Does Not in Itself Prove the Existence of Antimatter

    Why Antihydrogen and Antimatter Are Different As Paul Dirac Realized, the Existence of Antihydrogen Does Not in Itself Prove the Existence of Antimatter

    ANTIMATTER Why antihydrogen and antimatter are different As Paul Dirac realized, the existence of antihydrogen does not in itself prove the existence of antimatter. A look through the history of the subject, and in particular the role played by the CPT theorem, shows that ultimately it came down to experiment to prove the existence of antimatter through the discovery of the antideuteron at CERN in 1965. “Those who say that antihydrogen is antimatter should realize that we are not made of hydrogen and we drink water, not liquid hydro- gen.” These are words spoken by Paul Dirac to physicists gathered around him after his lecture “My life as a Physicist” at the Ettore Majorana Foundation and Centre for Scientific Culture in Erice in 1981 – 53 years after he had, with a single equation, opened new horizons to human knowledge. To obtain water, hydrogen is, of course, not sufficient; oxygen with a nucleus of eight protons and eight neutrons is also needed. Hydrogen is the only element in the Periodic Table to consist of two charged particles (the electron and the proton) without any role being played by the nuclear forces. These two particles need only electromagnetic glue (the photon) to form the hydrogen atom. The antihydrogen atom needs t wo antipar- ticles (antiproton and antielectron) plus electromagnetic antiglue (antiphoton). Quantum electrodynamics (QED) dictates that the photon and the antiphoton are both eigenstates of the C-operator (see later) and therefore electromagnetic antiglue must exist and act like electromagnetic glue. Dirac surrounded by young physicists in Erice after his lecture “My Life If matter were made with hydrogen, the existence of antimatter as a Physicist”.
  • CMB-S4 Workshop SLAC Feb 2017

    CMB-S4 Workshop SLAC Feb 2017

    Cosmology with CMB-S4 Workshop DOE/NSF Project Experience Key Ingredients to Success SLAC National Accelerator Laboratory February 27, 2017 Jim Yeck Outline • Personal Experience • DOE Office of Science (SC) Experience - Projects after the Superconducting Super Collider - DOE SC management perspectives • NSF Large Project Experience - IceCube - Large Hadron Collider Experiments • Satisfying Needs of Project Stakeholders • Next Steps 2 My projects Cost/Circa Infrastructure Project Purpose for CD-3 Funding Role Compact Ignition Tokamak (CIT) at Fusion Energy $330M DOE Acting Project Princeton Plasma Physics Lab Science 1988 DOE Manager Relativistic Heavy Ion Collider $600M DOE Project (RHIC) at Brookhaven Lab (BNL) Nuclear Physics 1991 DOE + NSF + Int Manager US Large Hadron Collider (USLHC) High Energy $530M DOE/NSF Project In-kind delivered to CERN Physics 1998 DOE & NSF Director IceCube Neutrino Observatory at Particle $300M U of Wisconsin -– South Pole Astrophysics 2005 NSF + Int Project Director National Synchrotron Light $900M BNL - Deputy Source II at BNL Photon Source 2008 DOE + Other Project Director Deep Underground Science and Physics, Biology, $750M U of Cal – Associate Engineering Laboratory (DUSEL) and Engineering 2010 NSF + Private Project Director European Spallation Source (ESS) $2,500M ESS ERIC – Director in Sweden Neutron Source 2014 European States General & CEO 3 Key Ingredients to success Facility is a priority of the science community! Strong funding agency commitments and host role Project leaders viewed as enabling
  • The Discovery of the Higgs Boson at the LHC

    The Discovery of the Higgs Boson at the LHC

    Chapter 6 The Discovery of the Higgs Boson at the LHC Peter Jenni and Tejinder S. Virdee 6.1 Introduction and the Standard Model The standard model of particle physics (SM) is a theory that is based upon principles of great beauty and simplicity. The theory comprises the building blocks of visible matter, the fundamental fermions: quarks and leptons, and the fundamental bosons that mediate three of the four fundamental interactions; photons for electromag- netism, the W and Z bosons for the weak interaction and gluons for the strong interaction (Fig. 6.1). The SM provides a very successful description of the visible universe and has been verified in many experiments to a very high precision. It has an enormous range of applicability and validity. So far no significant deviations have been observed experimentally. The possibility of installing a proton-proton accelerator in the LEP tunnel, after the e+e− programme, was being discussed in the 1980’s. At the time there were many profound open questions in particle physics, and several are still present. In simple terms these are: what is the origin of mass i.e. how do fundamental particles acquire mass, and why do they have the masses that they have? Why is there more matter than anti-matter? What is dark matter? What is the path towards unification of all forces? Do we live in a world with more space-time dimensions than the familiar four? The LHC [1, 2] was conceived to address or shed light on these questions. P. Jenni CERN, Geneva, Switzerland Albert-Ludwigs University Freiburg, Freiburg im Breisgau, Germany T.
  • Electron-Positron Pairs in Physics and Astrophysics

    Electron-Positron Pairs in Physics and Astrophysics

    Electron-positron pairs in physics and astrophysics: from heavy nuclei to black holes Remo Ruffini1,2,3, Gregory Vereshchagin1 and She-Sheng Xue1 1 ICRANet and ICRA, p.le della Repubblica 10, 65100 Pescara, Italy, 2 Dip. di Fisica, Universit`adi Roma “La Sapienza”, Piazzale Aldo Moro 5, I-00185 Roma, Italy, 3 ICRANet, Universit´ede Nice Sophia Antipolis, Grand Chˆateau, BP 2135, 28, avenue de Valrose, 06103 NICE CEDEX 2, France. Abstract Due to the interaction of physics and astrophysics we are witnessing in these years a splendid synthesis of theoretical, experimental and observational results originating from three fundamental physical processes. They were originally proposed by Dirac, by Breit and Wheeler and by Sauter, Heisenberg, Euler and Schwinger. For almost seventy years they have all three been followed by a continued effort of experimental verification on Earth-based experiments. The Dirac process, e+e 2γ, has been by − → far the most successful. It has obtained extremely accurate experimental verification and has led as well to an enormous number of new physics in possibly one of the most fruitful experimental avenues by introduction of storage rings in Frascati and followed by the largest accelerators worldwide: DESY, SLAC etc. The Breit–Wheeler process, 2γ e+e , although conceptually simple, being the inverse process of the Dirac one, → − has been by far one of the most difficult to be verified experimentally. Only recently, through the technology based on free electron X-ray laser and its numerous applications in Earth-based experiments, some first indications of its possible verification have been reached. The vacuum polarization process in strong electromagnetic field, pioneered by Sauter, Heisenberg, Euler and Schwinger, introduced the concept of critical electric 2 3 field Ec = mec /(e ).
  • Scientific and Related Works of Chen Ning Yang

    Scientific and Related Works of Chen Ning Yang

    Scientific and Related Works of Chen Ning Yang [42a] C. N. Yang. Group Theory and the Vibration of Polyatomic Molecules. B.Sc. thesis, National Southwest Associated University (1942). [44a] C. N. Yang. On the Uniqueness of Young's Differentials. Bull. Amer. Math. Soc. 50, 373 (1944). [44b] C. N. Yang. Variation of Interaction Energy with Change of Lattice Constants and Change of Degree of Order. Chinese J. of Phys. 5, 138 (1944). [44c] C. N. Yang. Investigations in the Statistical Theory of Superlattices. M.Sc. thesis, National Tsing Hua University (1944). [45a] C. N. Yang. A Generalization of the Quasi-Chemical Method in the Statistical Theory of Superlattices. J. Chem. Phys. 13, 66 (1945). [45b] C. N. Yang. The Critical Temperature and Discontinuity of Specific Heat of a Superlattice. Chinese J. Phys. 6, 59 (1945). [46a] James Alexander, Geoffrey Chew, Walter Salove, Chen Yang. Translation of the 1933 Pauli article in Handbuch der Physik, volume 14, Part II; Chapter 2, Section B. [47a] C. N. Yang. On Quantized Space-Time. Phys. Rev. 72, 874 (1947). [47b] C. N. Yang and Y. Y. Li. General Theory of the Quasi-Chemical Method in the Statistical Theory of Superlattices. Chinese J. Phys. 7, 59 (1947). [48a] C. N. Yang. On the Angular Distribution in Nuclear Reactions and Coincidence Measurements. Phys. Rev. 74, 764 (1948). 2 [48b] S. K. Allison, H. V. Argo, W. R. Arnold, L. del Rosario, H. A. Wilcox and C. N. Yang. Measurement of Short Range Nuclear Recoils from Disintegrations of the Light Elements. Phys. Rev. 74, 1233 (1948). [48c] C.
  • Dispersion Relations in Gauge Theories with Confinement

    Dispersion Relations in Gauge Theories with Confinement

    EFI 95-54 MPI-Ph/95-82 Dispersion Relations in Gauge Theories with Confinement 1 Reinhard Oehme Enrico Fermi Institute and Department of Physics University of Chicago, Chicago, Illinois, 60637, USA 2 and Max-Planck-Institut f¨ur Physik - Werner-Heisenberg-Institut - 80805 Munich, Germany Abstract The analytic structure of physical amplitudes is considered for gauge the- ories with confinement of excitations corresponding to the elementary fields. Confinement is defined in terms of the BRST algebra. BRST-invariant, local, composite fields are introduced, which interpolate between physical asymp- totic states. It is shown that the singularities of physical amplitudes are arXiv:hep-th/9511007v1 1 Nov 1995 the same as in an effective theory with only physical fields. In particular, there are no structure singularities (anomalous thresholds) associated with confined constituents, like quarks and gluons. The old proofs of dispersion relations for hadronic amplitudes remain valid in QCD. 1Plenary talk presented at the XVIIIth International Workshop on High Energy Physics and Field Theory, Moscow-Protvino, June 1995. To be published in the Proceedings. 2Permanent Address It is the purpose of this talk, to give a survey of the problems involved in the derivation of analytic properties of physical amplitudes in gauge theories with confinement. This report is restricted to a brief resum´eof the essential points discussed in the talk. 3 Dispersion relations for amplitudes describing reactions between hadrons, and for form factors describing the structure of particles, have long played an important rˆole in particle physics [3, 4, 5, 6]. Analytic properties of Green’s functions are fundamental for proving many important results in quantum field theory.
  • Lhcb Prepares for RICH Physics

    Lhcb Prepares for RICH Physics

    I n t e r n at I o n a l J o u r n a l o f H I g H - e n e r g y P H y s I c s CERN COURIERV o l u m e 47 n u m b e r 6 J u ly/a u g u s t 2 0 07 LHCb prepares for RICH physics NEUTRINOS LHC FOCUS InSIDE STORY Borexino starts On the trail of At the far side to take data p8 heavy flavour p30 of the world p58 CCJulAugCover1.indd 1 11/7/07 13:50:51 Project1 10/7/07 13:56 Page 1 CONTENTS Covering current developments in high- energy physics and related fields worldwide CERN Courier is distributed to member-state governments, institutes and laboratories affiliated with CERN, and to their personnel. It is published monthly, except for January and August. The views expressed are not necessarily those of the CERN management. Editor Christine Sutton CERN CERN, 1211 Geneva 23, Switzerland E-mail [email protected] Fax +41 (0) 22 785 0247 Web cerncourier.com Advisory board James Gillies, Rolf Landua and Maximilian Metzger Laboratory correspondents: COURIERo l u m e u m b e r u ly u g u s t V 47 N 6 J /A 20 07 Argonne National Laboratory (US) Cosmas Zachos Brookhaven National Laboratory (US) P Yamin Cornell University (US) D G Cassel DESY Laboratory (Germany) Ilka Flegel, Ute Wilhelmsen EMFCSC (Italy) Anna Cavallini Enrico Fermi Centre (Italy) Guido Piragino Fermi National Accelerator Laboratory (US) Judy Jackson Forschungszentrum Jülich (Germany) Markus Buescher GSI Darmstadt (Germany) I Peter IHEP, Beijing (China) Tongzhou Xu IHEP, Serpukhov (Russia) Yu Ryabov INFN (Italy) Barbara Gallavotti Jefferson Laboratory (US) Steven Corneliussen JINR