ccnn COURIER International journal of high energy physics History of CERN, III Edited by J. Krige
"The present volume continues the story of the history of CERN, concentrating on the years between the • mid 1960s and the late 1970s, Contents: Part I. Interactions. CERN from the mid-1960s to tie late 1970s (1 Krige). Gargamelle and BEBC How Europe's last two giant bubble chambers were chosen (D. Pestre). The difficult decision, taken in the 1960s, to construct a 3-400 GeV proton synchrotron in Europe (D, Pestre), The intersecting storage rings. The construction and operation of CERN's second large machine and a survey of its experimental programme. The relationship between CERN and its Visitors' in the 1970s (J. Krige), The ppbar project I, The collider (I Krige), The ppbar project It The organization of experimental work (J. Krige). Part 11 Physics Results. Physics in the CERN theory division (J. Hiopoubs). The SC: Isolde and nuclear structure {G> Hansen), Experimental studies of weak interactions (K. Winter), Part III, Technologies. The development of accelerator art and expertise at CERN: 1960-1980. Twenty fruitful years (M. CrowieyMlling), The development of electronic position detectors at CERN (1964 - late 1970s) (I Gambaro). Name index. Subject index.
1996 700pages Price: NLG 375.00 (US$234,50) Hardbound ISBN0*444*896554 ALREADY PUBLISHED: History of CERN, II History of CERN, I Volume II - Building and Running the Volume I - Launching the European Laboratory, 1954-1965 Organization for Nuclear Research
By A. Hermann, J. Krige, U. Mersits and By A. Hermann, J. Krige, U. Mersits and D. Pestre D. Pestre
With a contribution by L Weiss With a contribution by L Belloni "The authors... have put together this account of a complex mix "This is a very valuable book. It gives a clear, readable, of scientific, technical, and political achievements in a masterly well-documented and... accurate and impartial account of the fashion... can be highly recommended to all who want to read history of a remarkable organization... The history of CERN is how CERN started on the path to become a world class interesting for its own sake but the importance of this book goes laboratory and a leader in its field of research." beyond that." Contemporary Physics Nature Contents: Part I. An Overview of the First Decade of Contents: Part I - The Post-War Emergence of CERN. Part II. Physics and Engineering at CERN. High-Energy Physics. Part II - The Prehistory of CERN, Collection of Documents and Photographs of Historic 1949 - February 1952. Part III - The Provisional CERN, Interest. Part III. Planning and Managing Research at February 1952 - October 1954. Part IV - National CERN. Part IV. Concluding Remarks. Decisions to Join CERN. Part V - Concluding Remarks. 1990 xxii + 880 pages Hardbound ISBN 0-444-88207-3 1987 xxii + 600 pages Hardbound ISBN 0-444-87037-7 Price: NLG 329.00 (US$205.75) Price: NLG 351.00 (US$219.50)
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CERN Courier, January/February 1997 ISSN 0304-288X Advertising enquiries Europe Volume 37 No. 1 Micheline Falciola January/ Covering current developments in high energy Advertising Manager February 1997 CERN physics and related fields worldwide CH-1211 Geneva 23, Switzerland Editor: Gordon Fraser CERN.COURIER® CERN.CH Tel.: +41 (22) 767 4103 Production and Advertisements: Fax: +41 (22) 782 1906 Micheline Falciola [email protected] Rest of the world Advisory Board: E.J.N. Wilson (Chairman), E. Lillestol, Guy Griffiths M. Neubert, D. Treille; with L. Foa, Advertising Manager, USA E.M. Rimmer International Publishers Distributor World Wide Web http://www.cern.ch/CERN/Courier/ 820 Town Center Drive LANGHORNE PA 19047 Tel.: (215) 750-2642 Economy class physics Fax: (215) 750-6343 Cutting to the bone to preserve CERN's LHC Distributed to Member State governments, institutes and laboratories affilliated with CERN, and to their personnel. Around the Laboratories General distribution CERN: One year of LEP2 / Over the muon / In the right channel / Jacques Dallemagne Goliath and the North-West passage CERN, 1211 Geneva 23, Switzerland In certain countries, to request copies or to NIKHEF: More AmPS make address changes contact: Polarized electrons at Amsterdam machine
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Italy Physics monitor Mrs. Pieri or Mrs. Montanari INFN, Casella Postale 56 A cold welcome 00044 Frascati, Roma Cryogenics symposium United Kingdom DETECTORS: Scintillating fibres at work Su Lockley Rutherford Appleton Laboratory, Spin physics symposium Chilton, Didcot, Oxfordshire OX11 0QX Gaps in understanding USA/Canada Spotlight on diffractive physics... Janice Voss Desperately seeking unseen SUSY Creative Mailing Services ... and supersymmetry P.O. Box 1147 St. Charles, Illinois 60174 Tel.: 630-377-1589/ Fax: 630-377-1569 FERMILAB: First antihydrogen CERN COURIER is published monthly except January and August in English and Matter symmetry French editions. The views expressed in the Journal are not necessarily those of the Looking-glass particles and symposium report CERN management. Printed by: Drukkerij Lannoo nv DESY Theory Workshop 8700 Tielt, Belgium Published by: Bookshelf European Laboratory for Particle Physics CERN, 1211 Geneva 23, Switzerland tel.: +41 (22)767 61 11, People and things telex: 419 000 CERN CH, telefax: +41 (22) 767 65 55 CERN COURIER only: tel. +41 (22) 767 41 03, telefax +41 (22) 782 19 06 Cover photograph: Sub-target array of the NA50 heavy ion experiment at CERN, showing both sides of the retracted recognition system to identify USA: Controlled Circulation which target element is 'hit'. Cherenkov light produced by particles in the quartz Periodicals postage paid at St. Charles, slabs is transmitted to photomultipliers by optical fibre bundles (Photo Guy Illinois m< B Jacquet, IPN-Lyon).
CERN Courier, January/February 1997 Family
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t its December meeting, CERN's from the Department of Energy of the discovery of antihydrogen at A governing body, Council, took (DOE) of $200 million, and the LEAR low energy antiproton ring. the important decision that the contributions from the DOE and the Another LEAR result had been the Laboratory's big project for the next National Science Foundation for the confirmation by the Crystal Barrel millenium, the LHC proton collider, ATLAS and CMS experiments at experiment of a 'glueball', a shall be completed in a single stage LHC totalling $330 million. CERN subnuclear state made of gluons, the and planning shall proceed on the Council approved this text. particles which carry the inter-quark basis that the LHC will be commis However this impressive LHC force, but no quarks. The heavy ion sioned in 2005. blueprint for physics in the next experiments at the SPS synchrotron When a green light for LHC had first millennium was approved against a had uncovered important additional been illuminated at the December sad background of budget evidence that the long-awaited 1994 Council meeting, the reductions. Early last year, CERN quark-gluon plasma, the high understanding was for a two-stage management had been temperature precursor of everyday project, with an initial intermediate congratulating itself on having nuclear matter, was within reach, energy and the collider only attaining obtained initial LHC approval and while the LEP electron-positron its design energy of some 7 TeV per gaining significant assurances of collider provided its first batch of beam in 2008. However at that time backing from non-Member States. pairs of W particles, the electrically Council said that if sufficient interest Then in an August bombshell, charged carriers of the weak nuclear and financial commitment were Germany unexpectedly sought a force. forthcoming from non-Member reduction in its contribution to the Applauding this latest research States, the project might be CERN budget. harvest, Llewellyn Smith hinted that completed in a single stage. This proposal naturally received a future such summaries would risk Since then, non-Member State hostile reception at CERN but also being less impressive. The LEAR low interest and commitment for the LHC did not find favour with most other energy antiproton ring is now closed have snowballed. Japan made an Member States. However after and the experimental programme at initial generous contribution of 5 intense discussion, it was decided the SPS is gradually being run down, billion yen, and at the December that while LHC funding would remain sacrificial lambs to the LHC. 1996 Council meeting pledged a intact, CERN's overall budget, further contribution of 3.85 billion yen compared to that foreseen in 1994, (some 33 million dollars), subject would be reduced by an however to final approval by the unprecedented 7.5% in 1997, with Japanese parliament. At the Council reductions increasing to 8.5% in meeting, Japanese delegate Daisuke 1998-2000, and to 9.3% thereafter. Machida said The Japanese Take-home pay of CERN staff will be government hopes that this decision cut by 2.5%. substantially contributes to the However Council gave CERN success of future work at this famous management additional flexibility to research centre'. bankroll the LHC, with payments Last year, agreements for the LHC extended to 2008 if need be. accelerator had also been signed in With manpower and expenditure for March with India with a net value for LHC untouched, these cuts fall on CERN of $12.5 million, in June with the remainder of the research Russia (50 million dollars), and with programme. In his traditional end- the Canadian TRIUMF Laboratory for year summary of scientific an in-kind contribution with a value of achievements, CERN Director $30 million Canadian. General Chris Llewellyn Smith In the US, a cooperation agreement proudly pointed to an impressive has been drafted outlining a array of results. The tone for 1996 contribution to the LHC accelerator had been set with the announcement
CERN Courier, January/February 1997 1 Over 500 beam position monitors around the 27-kilometre LEP ring trace carefully the circulating particles. This shows the difference between the electron and positron closed orbits. The horizontal plane (above) shows Around the Laboratories characteristic 'sawteeth' - the energy difference between the two beams - reaching a maximum when one beam receives a radiofrequency kick while the other is just arriving after experiencing the inexorable slow energy loss due to synchrotron radiation. The vertical plane (below) shows how the circulating bunch trains are bumped by electrostatic separators to avoid unwanted collisions between electron and positron bunches.
CERN One year of LEP2
EP2, as CERN's LEP electron- L positron collider is now called to underline its higher beam energies, finished 1996 operations in mid- November and the four big experiments retired to continue carefully analysing the new physics conditions enjoyed during the first complete year of LEP2 operations. LEP2's 1996 debut was a major encouraging score as the machine failures. success, demonstrating the had to remain silent for long periods The cautionary radiofrequency limit impressive accomplishments of its while its additional superconducting meant that four bunches per beam superconducting acceleration power. power was being installed. were used for the most part. After six years faithfully logging LEP LEP2's 176 superconducting However when this limit was raised, electron-positron annihilations into radiofrequencycavities and couplers operation switched to bunch trains, Zs, the neutral carriers of the weak worked well, but delicate forced with four trains of two bunches per force, around 91 GeV, 'LEP 1.5', oscillation effects effectively limited beam. flexing its first superconducting the electron-positron beam currents However higher LEP2 energies radiofrequency muscles, debuted in which could be handled. were expected to increase the beam 1995 at a higher energy of 140 GeV In the continual search for improved size and a compensatory new 1087 (70 GeV per beam). operational conditions, LEP has tried 90° low emittance tune was With additional superconducting out a series of beam tunes. 1996 scheduled. At the beginning of power on board, last summer the operation began with a mixed 1087 November, LEP was shut down fully-fledged LEP2 ran for six weeks 60° horizontal/vertical phase advance again briefly for its sextupole at 161 GeV (80.5 GeV per beam), using a beam configuration of four magnets to be recabled to handle giving the four experiments, Aleph, trains of two bunches per beam. these new conditions. While the goal Delphi, L3 and Opal, their first taste However this did not live up to was to optimize the beam size of W pairs, the electrically charged expectations and operation shifted to (emittance), the operations crew carriers of the weak force (October a 90760° tune. This was a were disappointed when the new 1996, page 18). spectacular success, with luminosity scheme appeared to have possible This initial W pair collection run increasing faster than it ever had implications for beam stability. The halted as scheduled in mid-August before, and a maximum dynamic aperture, the range of for LEP2 to reinforce its instantaneous luminosity of 3.4 x 1031 running conditions under which superconducting radiofrequency per sq cm per s. After valiant beams are stable, was much more power by the addition of 28 more radiofrequency efforts to improve the restricted than had been expected. cavities, and on 19 October the reliability of an extremely complex In January, LEP team traditionally machine duly responded with a new system, LEP2's act began to look migrate to a workshop in Chamonix high energy of 172 GeV (86 GeV per very together, and the operations in the French Alps to review the past beam). The integrated luminosity (a crew were once more able to enjoy year's achievements and thrash out measure how many electron-positron the satisfaction of choosing the plans for the coming year. collisions were delivered for physics) moment to dump coasting beams On the machine front, with no more for the year reached 24 inverse and replace them with fresh particles, empty space for extra picobarns, a modest total by LEP rather than being the hapless victims superconducting cavities to be standards, but nevertheless an of teething problems and equipment installed, a major phase of
2 CERN Courier, January/February 1997 Around the Laboratories
The EMC spectrometer in 1978 during CERN's first muon physics run. At the back of the hall (top right) can be seen CERN's other big muon experiment, BCDMS. (Photo CERN X 500-5-78)
superconducting cavity installation is complete. To take the beam energy higher, this winter 34 of LEP's 120 conventional radiofrequency accelerating cavities will be removed and replaced by 32 superconducting ones, opening up the prospect of 94 GeV per beam for 1997.
Over the muon
n 1974, 45 physicists from 13 institutions put their names to CERN proposal SPSC/P18, and a new era in particle physics history was born. The European Muon Collaboration, EMC, grew to over 70 collaborators, and collected its first data in 1978 with the new Super Proton Synchrotron high intensity muon beam. Last September, the for physics at the Large Electron hadron collider experiments. Spin Muon Collaboration, SMC, final Positron collider, LEP. A new In the early days of CERN's muon successor to the EMC, had its final collaboration took over and upgraded programme, two experiments shared run, bringing to an end a 22 year era the apparatus, ready to look deeper the same beam and the same hall. of muon physics with the EMC into questions raised by the The EMC was first in line and spectrometer. unexpected EMC results. The new downstream was another major By today's standards, 70 collaboration christened itself the experiment, initially led by Carlo collaborators seems modest, but the New Muon Collaboration, NMC, and Rubbia and named BCDMS after the EMC proposal came at a turning ran until 1991 before passing the initials of its collaborating institutions. point in particle physics research. baton to the Spin Muon This arrangement may appear to be For the first time, collaborations Collaboration. uneven, with EMC getting beam building electronic counter CERN's muon programme was priority. But CERN's muon beam experiments were attaining cast lists established with the goal of delivered around 10 million muons in only previously seen in bubble measuring the momentum each two second pulse, and for each chamber collaborations. distribution of quarks inside pulse, just 100 muons collided in the The original EMC, with Erwin nucleons, the so-called nucleon EMC target, leaving plenty for Gabathuler as elder statesman, structure functions. This initial task BCDMS. stayed together until 1986, publishing was to provide essential input for In the simplest picture of nucleons, 71 papers and twice confounding the understanding the results of proton- a proton or a neutron contains three world of physics with unforeseen proton collisions at the ISR, as well quarks. But reality is a little more results. The paper announcing one as the proton-antiproton collisions complex, the gluons sticking these of these was still in the top-20 chart foreseen at CERN's Super Proton three so-called valence quarks of most cited high energy physics Synchrotron collider. Structure together sometimes split momentarily papers seven years after publication function results have lost none of into pairs of quarks and antiquarks. (March 1995, page 21). their importance in the intervening This leads to a foaming 'sea' of low- Its initial task complete, in 1986, the years, and will be equally as vital at momentum quark-antiquark pairs as EMC fragmented as members the Large Hadron Collider, LHC, as well as the three high-momentum migrated to experiments preparing they were at previous generations of valence quarks.
CERN Courier, January/February 1997 3 Around the Laboratories
EMC and BCDMS measured the the wayside, but the jury is still out on much as a hundred times larger than distribution of momenta of all these what the real cause of the EMC silicon at high energy and large quarks by firing high energy muons effect might be. deflection angles. deep inside nucleons, and measuring The SMC, as its name suggests, CERN does not yet use bent the way they bounced off the quarks concentrated on the spin crisis, and crystals to extract the beams for inside. Both experiments started off devised a state-of-the-art polarized actual experiments, but a series of using targets of heavy nuclei, target specifically for the job. SMC 'machine development' trials have maximizing the probability that an results reveal that only one fifth of the extensively explored the feasibility of incident muon would strike a proton proton's spin comes from quarks. this approach. In 1996, proton beams or neutron. They later used targets The rest, it is now believed, must be of 14, 120 and 270 GeV were of deuterium, where the nucleons are due at least in part to spinning extracted. In another recent much less densely packed. gluons. development at CERN, a high energy Physicists expected little difference For now, muon physics takes a beam of lead ions, fully stripped of between the structure functions from break at CERN. But with the proton's electrons (82-fold charged ions of light nuclei and those from heavy spin still a mystery, experiments are 270 GeV per charge, giving a total ones, but when EMC physicists at the planning stage to carry on energy of 22 TeV) was successfully compared their iron and deuterium where SMC has just left off. extracted from the SPS by a bent data, they found a rather different crystal, the first time that such high picture. The quarks inside nucleons energy ions have ever been handled embedded in a heavy iron nucleus In the right channel in this way. behave very differently from those Other tests, performed by an inside the almost free nucleons in a hanks to 'channeling' - the Aarhus-CERN collaboration in an deuterium nucleus. This effect came T steering and deflection of external SPS beamline, showed that to be called the EMC effect, and was particles by the strong fields due to 33 TeV lead ions (400 GeV per the first surprise to come out of the atomic symmetry in crystals - a charge) are deflected by crystals to CERN's muon programme. tiny crystal weighing a few grams, the same extent as protons of an The second came in a later when mechanically bent by just a few equivalent momentum. These experiment by the EMC in which microns, can have the same effect on crystals, typically 50 millimetres in polarized muons were fired at charged particles as a bending the beam direction, 10 mm wide and polarized protons. Just like miniature magnet weighing several tons. 1 mm thick, can bend high energy spinning tops, protons spin about This effect has been investigated beams through 20 milliradians and their axes, and by scattering for many years. At Serpukhov, near more, enough to deflect the beam by polarized muons from polarized Moscow, proton beams have actually 20 metres over a kilometre. protons, information can be gleaned been extracted and delivered to about the spin of the quarks inside. It various experiments in this way, was once thought that the proton's while at CERN, a bent crystal is used spin comes simply from adding up in a novel orientation to derive the 4-1 05 the spins of the quarks, but the EMC twin beams for the NA48 experiment measurement showed that the quark measuring CP violation. Bent crystals o 2-1 o5 spins largely cancel out, leaving the are also being studied at Dubna and proton's spin in crisis. Fermilab. CD The EMC's successors have Work so far has concentrated on E 0 _^ studied these effects in depth. NMC the relatively easily manufactured -2.0 0.0 2.0 4.0 6.0 concentrated largely on the EMC silicon crystals, but in 1996 an deflection angle [mrad] effect, which is now extremely well experiment at CERN used measured. Theoreticians have been germanium. Its heavier nuclei with a Crystal clear - a 33 TeV beam of lead ions (400 GeV per charge) at CERN was steered scratching their heads to try and bigger charge have a greater effect through four milliradians using a bent crystal. explain it, and many models have on steering the beam particles, giving About 15% of the beam particles were been proposed. Some have fallen by an effective bending efficiency as channeled and deflected.
4 CERN Courier, January/February 1997 Around the Laboratories
Comparing nucleus-nucleus collisions to those of protons on nuclei, the three WA experiments based on the Omega spectrometer find that particle production does increase with strangeness content - there are more lambdas (one unit of strangeness) than pions (no strangeness), and more ksis (two units of strangeness) than lambdas.
Goliath and the North This magnet, originally built at Saclay, was used in a west passage photoproduction experiment in the North Area and subsequently shifted n the reorganization of fixed target to the West Area for work with WA93/ I physics at CERN's SPS 98. With its career path in the West synchrotron in the runup to CERN's area now at an end, Goliath is to LHC proton collider (November 1995, make the trek back to the North. page 5), the heavy ion programme is being focused on the North experimental area. Research with heavy ions began at the SPS ten years ago, and has been NIKHEF traditionally split between the West and the North experimental areas. In More Am PS the West area, a valuable series of experiments has been carried out uring a preliminary run last using the general-purpose Omega D September, longitudinally spectrometer - WA85 using sulphur polarized electrons were stored in the beams on a tungsten target, WA94 Amsterdam Pulse Stretcher (AmPS), using sulphur beams on a sulphur find that particle production does the 210-metre electron storage ring target, and WA97 using lead beams increase with strangeness content - at the Dutch NIKHEF research and a lead target. there are more lambdas (one unit of centre. The West area has also been the strangeness) than pions (no Produced from a strained crystal of home of several other heavy ion strangeness), and more ksis (two gallium arsenide using a circularly studies, including the large WA93/98 units of strangeness) than lambdas. polarized laser beam, the polarized spectrometer, with the Plastic Ball More recently, WA97 has seen signs electrons were then grouped into detector, originally used at the of increased omega production (three bunches. After acceleration to 400 Berkeley Bevalac, housed inside the units of strangeness) compared with keV, the electron spin orientation was Goliath magnet together with a ksis. This strangeness concentration manipulated by an arrangement of downstream lead-glass calorimeter. suggests that quark-gluon plasma is electric and magnetic fields. Finally, A particular objective of the series not that far away. the electrons were accelerated to of experiments at the Omega To continue this investigation, 600 MeV and injected into AmPS. spectrometer has been to measure NA57, a new experiment by a At present, the system is optimized the yields of particles carrying the collaboration of scientists from the for the first series of experiments this strangeness quantum number - Czech Republic, France, Italy, the year. Amsterdam is the first place in kaons and hyperons. An increased Netherlands, Norway, Russia, the world where longitudinally strangeness yield is expected to be Slovakia and the UK, as well as polarized electrons are actually one signal for the onset of the long- CERN, will build a new spectrometer injected and stored for long periods awaited quark-gluon plasma - a in the SPS North Area. of time. (Longitudinally polarized 'soup' formed when the nuclear The new experiment will also use a electrons produced the same way at matter formed in the collision gets so lower ion beam energy, 40 GeV per the SLAC linear accelerator, hot and so compressed that the nucleon, as well as the previous 160 Stanford, are only briefly stored in a boundaries between individual GeV, extending the coverage of damping ring en route to their once- subnuclear particles melt. possible quark-gluon transition. only passage down the linac.) Comparing nucleus-nucleus The planned setup resembles In most larger storage rings, beams collisions to those of protons on WA97, with a spectrometer of transversely polarized electrons nuclei, the three WA experiments consisting of series of silicon pixel are created via the Sokolov-Ternov based on the Omega spectrometer arrays inside the Goliath magnet. effect (when electrons flip their spin
CERN Courier, January/February 1997 5 Around the Laboratories
Injector for the 210-metre Amsterdam Pulse Stretcher (AmPS) electron storage ring at the Dutch NIKHEF research centre which now stores longitudinally polarized electrons. On the left is the gun chamber which produces 100 keVpolarized electrons. The extracted electrons are bent through 90° and pass through a Z-shaped spin manipulator. Top right is a Mott polarimeter. The source was built at the Budker Institute, Novosibirsk, which has been closely cooperating with NIKHEF since 1986. after emitting synchrotron radiation). This happens more often for electrons with spins parallel to the magnetic field in the ring than for those with anti-parallel spin, resulting in an excess of the latter. In these cases, longitudinal polarization has to be established using special spin rotator magnets, as is done at the HERA electron ring at DESY, Hamburg. But producing polarization by synchrotron radiation depends on beam energy and on the strength of the field, and in the AmPS configuration would take up to a week. Preference was therefore given to direct production of longitudinally polarized electrons in a gallium arsenide source. The source was built at the Budker Institute, Novosibirsk, which has been closely cooperating with NIKHEF since 1986. In maintaining the required ultra-high vacuum (10-9 Pa), NIKHEF also profits from previous experience at SLAC. Inside the storage ring, the longitudinal electron polarization is conserved by a 'Siberian Snake'. This superconducting solenoid, also built in Novosibirsk, ensures that the electrons arrive properly polarized at the target. The overall polarization is measured using Compton- backscattering and found to be the same as at the source. For the first experiments, using a polarized internal helium-3 target, NIKHEF aims for a current of more than 100 mA. The polarized beam is accelerated in 0.7 microsecond pulses and each
Inside the AmPS storage ring, longitudinal electron polarization is conserved by this 'Siberian Snake' superconducting solenoid, also built at Novosibirsk.
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DESY Director Bjorn Wiik is the new chairman of ICFA - the International Committee for Future Accelerators. (Photo Patrick Piel)
pulse fills the entire storage ring. A There is a worldwide effort to continuous beam of 100 mA is then measure this charge form factor - obtained by "stacking" the individual experiments are being prepared at pulses on top of each other. Mainz, CEBAF/Jefferson and MIT. It is a challenge to reach a high However these use external targets stacking efficiency, demanding that with extracted polarized electron the beam shifts as little as possible. beams. Such shifts easily occur when a new bunch is injected and may lead to losses. This is made more difficult since there is little room: the beam ICFA must pass through the internal target, Collaboration a tube 40 cm long and only 15 mm wide. ith international collaboration This target, built at NIKHEF, is of W now such an essential part of similar design to that used in the high energy physics, ICFA - the HERMES experiment at DESY. International Committee for Future Rarefied gas is pumped through a T- Accelerators - provides a useful shaped storage cell which is placed forum to discuss plans and exchange inside the beampipe. Atoms spend opinions. A key feature of the ICFA on average 5 ms in this open-ended calendar is its triennial 'perspectives' budget problem which will allow the cell. They are polarized beforehand seminar, and the fifth such meeting, LHC to be completed in a single by circularly polarized laser beams in held at the Japanese KEK Laboratory stage as early as possible". (See combination with a weak external from 15-18 October, reflected current page 1.) magnetic field. The target thickness objectives and concerns. Much of the progress of the past 25 inside the storage cell is about 2 The main official statement said years has come because of the x1015 atoms per sq cm and the The meeting focused on the high different capabilities of two types of polarization is about 50%. There is energy frontier. The LHC proton accelerator: hadron and electron no background from scattering in the collider project at CERN is essential colliders. Thus the second major target walls. For the same reason low for progress in the field and ICFA focus of the seminar was on progress energy recoil particles can be hopes that it will be completed as in developing the technology that will detected and this allows different early as possible. It will address allow the construction of an electron final states to be discerned. today's key questions and open a linear collider that will complement Scattered electrons are detected in new energy domain. Its importance is the LHC. A well-coordinated research the 20-ton Big Bite detector built at indicated by the commitment of and development programme has the Budker Institute. The experiments CERN non-Member States to support been underway for many years. It aim to compare the magnetic both the facility and the experiments. now appears that an engineering moment of helium-3 with that of the The LHC is becoming a true world design study can begin in the next neutron. The helium-3 nucleus can, facility. We note with concern recent few years that will result in a proposal to a good approximation, be indications of possible problems in for a specific project. We believe that described as two protons with anti- CERN Member States with LHC such a facility should be realized as a parallel spin and one neutron. The funding. Stable funding is important world-wide enterprise on a basis spin of the nucleus is then to a large for effective realization of such large developed jointly by interested extent equal to the neutron spin. projects. ICFA is therefore pleased to scientific communities and their Precision experiments at NIKHEF will note that the Member States recently governments. allow the small deviations to be "reaffirmed their strong and The seminar included reviews of the studied. unanimous support for the LHC ongoing programmes close to The polarization also gives a handle programme and their wish to find a completion at the world's particle on the neutron charge distribution. quick and stable solution to the accelerator laboratories. Difficult
8 CERN Courier, January/February 1997 Around the Laboratories
financial climates in most regions of preparation, data-taking and analysis the world have required hard of their experiments has come to choices. Even so, ICFA notes depend crucially on access to good Schooltime impressive progress and anticipates computer networking. that the coming few years will result The availability of powerful low-cost ERN's calendar includes three in substantial advances in our distributed computing, the existence C regular schools - for understanding of the nature of matter of wide-area networks with the accelerators, computing and physics. and forces.' potential for high-bandwidth The 1996-7 academic year for As described in reports at the transmission, the availability of accelerator schools started with a meeting, research and development powerful networking software such course jointly organized by the CERN work on electron linear colliders is as the World Wide Web, and the Accelerator School and its opposite pushing ahead confidently on a increasing maturity of video numbers, KEKPAS in Japan and broad front, with different conferencing technology, have all USPAS in the United States. Over a accelerating radiofrequency bands changed the ways in which hundred participants, mostly but not and techniques being studied at widespread collaborations operate. exclusively from Asia, assembled in major laboratories in Europe, the US, The simultaneous use of WWW and early September to learn about "RF Japan and Russia (see page 34). video-conferencing forms an effective Engineering for Accelerators" at Also presented at the meeting were way for remote groups to participate Shonan Village Centre, Japan. plans for the LHC machine and its meaningfully in decision-making The team of lecturers consisted of experimental programme (which processes, and to collaborate experts from Asia, Europe and North could have bright prospects for significantly on data analysis and the America, as well as from Russia, developing supersymmetry - see preparation of publications. However which will become the fourth partner page 21), perspectives for possible for this to be really effective, in this World Accelerator School electron-positron physics, and adequate bandwidth must be when the next course in the series is advanced accelerator technologies. available on all of the frequently used held in Oxford, England, in 1998. Collaboration means paths, whether between the host One of the highlights of the school communication, and another area laboratory and the remote was a practical course on microwave where high energy physics has been institutions, or between the various measurements set up by John Byrd particularly influential is the field of remote institutions. and Fritz Caspers with the generous telecommunications, where the need ICFA notes with satisfaction that the support of Hewlett Packard who for large collaborations with wide major collaborations and host provided a number of network geographical spreads to share large laboratories involved have actively analysers and other microwave volumes of data has spawned major deployed these new modes of equipment. projects for high bandwidth communications and encouraged Soon after, in late October, CAS transmission, and in particular their use. ICFA urges that all held their "Introduction to Accelerator catalysed the development of the countries and institutions wishing to Physics" course in Cascais, Portugal, World Wide Web on the internet. participate even more effectively and in conjunction with the Laboratorio de Thus a second ICFA statement said fully in international high energy Instrumentagao e Fisica 'Over the past two decades, high physics collaborations should: review Experimental de Particulas, Lisboa. energy physics experiments have their operating methods to ensure This, the first of three courses become fewer in number and larger. they are fully adapted to remote designed to span the field up to the They are now often carried out at participation; and strive to provide the most advanced concepts, attracted laboratories far from home necessary communications facilities almost 100 participants - an institutions. Indeed, experiments are and adequate international encouraging sign that a new frequently on other continents. bandwidth.' generation is eager to contribute to The ability of researchers to On 1 January 1997, Fermilab accelerator technology. participate fully in the life of their Director John Peoples officially A number of the participants at home institutions and simultaneously handed over the chairmanship of these two schools had scholarships to fulfil their commitments to the ICFA to DESY Director Bjorn Wiik. funded by UNESCO for scientists
CERN Courier, January/February 1997 9 Around the Laboratories
and engineers from developing 12 hours of tutorials and laboratory near Marseilles (October 1996, page countries, including representatives work, by 23 speakers. 28). The 1997 school, organized by from China, India, Mexico, and The twentieth CERN School of CERN, JINR (Dubna, near Moscow), Nigeria. UNESCO will continue to Computing, at Pruhonice (Prague), and the Niels Bohr Institute, will be award these scholarships for future Czech Republic, from 17-30 August held at Naestved, Denmark, from 25 schools. is organized in collaboration with the May - 7 June. The 100 or so The academic year continues in Czech Academy of Sciences and the participants will come mostly from 1997 with a school on Magnet Charles University, Prague, and is CERN Member States or from Measurements (Measurement and also sponsored by the Computational laboratories closely associated with Alignment of Accelerator and Physics Group of the European CERN, but a few may come from Detector Magnets) in Anacapri, Italy, Physical Society. Covering countries further afield. Information organized in collaboration with INFN Information Systems, Real-Time from http://www.cern.ch/ Naples and local university Instrumentation, Software Production PhysicSchool/ or Susannah Tracy, departments, from 11-17 April, and and Visualisation, the School is open School of Physics, CERN/DSU, 1211 an Intermediate Level course on to postgraduate students and Geneva 23, Switzerland, phone +41 Accelerator Physics in Gjovik, research workers with a few years' 22 767 2724, fax +41 22 767 6760, Norway, organized in collaboration experience in elementary particle E-mail [email protected] or with the University of Oslo, from 1-12 physics, in computing or in related Tatyana Donskova, International September. fields. The 80 or so participants will Department. Joint Institute for Further information from the CAS come mostly from CERN Member Nuclear Research, RU-141980 Secretariat, Mrs. S. von Wartburg, States or from laboratories closely Dubna, Moscow Region, Russia, AC Division, CERN, CH-1211 associated with CERN, but a few phone +7 095 926 2252/7 096 21 Geneva 23, fax +41 22 767 5460, e- may come from countries further 63448, fax +7 095 975 2381/7 096 mail [email protected] afield. Applications (before 1 May) to 21 65 891, E-mail Meanwhile the 1996 CERN School Jacqueline Turner, School of [email protected] of Computing, from 8 - 21 Computing, CERN, 1211 Geneva 23, September, at the Hotel Zuiderduin, Switzerland Tel: +41 22 767 5049; Egmond aan Zee (Netherlands), was fax: +41 22 767 7155; e-mail: organized in collaboration with Computing.School ©cern.ch or via NIKHEF and the Dutch ASCI the Web: http://www.cern.ch/Physics/ (Advanced School for Computing and Conferences/C1997/CSC/ Imaging) and was the first CERN The European School of High School to be so combined. The total Energy Physics (formerly the CERN- number of participants was 91; 30 JINR School) was held last year from ASCI students, who participated in 1-14 September at Carry-le-Rouet, the first week only, and 61 non-ASCI. The impressive computing infrastructure included one SUN file server, 22 SUN workstations and 6 X-terminals workstations used for the laboratory work, and 4 PCs for e- mail. The themes treated were: A course on "RF Engineering for Accelerators", jointly organized by the CERN Accelerator Imaging, Parallel and Distributed School and its opposite numbers, KEKPAS in -4 Computing, Networks and Electronic Japan and USPAS in the United States, Highway, Data Acquisition Systems, attracted over a hundred students, mostly from Collaborative Engineering and Asia, to Shonan Village Centre, Japan. Here Simulation, Detectors/Imaging and East meets West as Wolfgang Vinzenz gets to grips with a network analyser under the Modern Programming Language watchful eye of Fritz Caspers (CERN) and Trends, in 47 one-hour lectures and Tsutomu Taniuchi (Spring 8, Japan).
10 CERN Courier, January/February 1997 Servant of peace Abdus Salam 1926-96
explain his and Lee's ideas about weak interactions breaking mirror After being unabie to symmetry. Mrs. Wu & Co. had not yet communicate for the past three embarked on their historic years by a crippling disease, experiment, but Salam, receptive to Abdus Salam, world physicist innovative ideas, was prepared to and Nobel laureate, died on 20 believe what Lee and Yang were November in Oxford. suggesting. As the US Air Force flight droned eastwards through the night, Salam's mind locked onto the problem. What could be special n September 1956 a bespectacled about the weak force to make it I 30-year old Pakistani physicist was mirror sensitive? returning to Cambridge, UK, from a Just a few months before the physics meeting in Seattle. Instead of Seattle physics meeting, Fred Reines taking a scheduled flight, Abdus and Clyde Cowan had sent a Salam boarded a US Air Force plane telegram to Pauli in Zurich - 'We are destined for a USAF base in Eng happy to inform you that we have land. In those days the US Air Force definitely detected neutrinos...'. After generously supported scientific 25 years, Pauli's prediction of a research in European universities, bizarre particle which hardly reacted and this support enabled physicists at all had been confirmed, and the student. However coming directly wishing to attend physics meetings in Seattle meeting had heard the from Pakistan he had little knowledge the US to take advantage of special implications of this physics. of the new quantum electrodynamics flights for US servicemen and their Thus neutrinos, as well as broken ideas of Feynman and Schwinger. families. mirror symmetry, were very much on Assimilating these ideas in record Although the European scientists Salam's mind that airborne time, he went on to apply them to were glad of the opportunity of cheap September night in 1956. 'I could not other particles. With several transatlantic travel, these flights were sleep,' recalled Salam. 'I kept landmark papers to his name and notoriously inconvenient and reflecting why Nature should violate with a future in physics assured, in uncomfortable. Check-in meant left-right symmetry in weak 1951 Salam nevertheless chose to travelling to a remote air base. interactions. Now the hallmark of return to Pakistan to become, at the Instead of tickets, there were 'flying most weak interactions was Pauli's age of 25, Professor at the College orders', multiple copies which had to neutrino. While crossing the Atlantic, and University of Panjab, Lahore. be successively surrendered at there came back to me a deeply Despite the local prestige of his new various stages of the journey. The perceptive question about the position, Salam found himself cut off planes were propeller-driven and neutrino which Rudolf Peierls had from the excitement and continual laboriously slow, some fifteen hours asked me at my Ph.D. examination stimulation of modern research. He to cross the Atlantic. The flights were a few years before - "Why is the realized this excitement was his frequently full of families with young neutrino's mass zero?".' (Peierls later lifeblood, and in 1954 left his native children, noisy and excited about the admitted that he did not know the land to return to Cambridge, this time prospect of moving from one country answer to that question himself, but as a lecturer. Salam was only to stay to another. The overnight west-east knowing Salam's reputation, he was at Cambridge for two years, but it trip was particularly uncomfortable. interested in the reaction it would was to there that he was returning But the European physicists receive.) from Seattle in 1956. appreciated this generous travel In Arabic, abd-us-salam means During that comfortless night in the opportunity. 'servant of peace'. In 1949, the air, Salam finally realized the answer At the Seattle physics meeting, young servant had arrived at Cam to Peierl's trick question. In his Salam had listened to Frank Yang bridge as an aspiring research cramped seat, Salam wrote down a
CERN Courier, January/February 1997 11 Servant of peace
Salam receives his 1979 Nobel prize from the King of Sweden.
prototype neutrino equation using isolation of a research retreat. Seeing standard Dirac formalism. Dropping how physics was developing, Salam the mass term, he immediately saw pushed Imperial theorists towards the that the remaining Dirac algebra problems of symmetry in particle could act like a switch - the neutrino classifications, and graduate student could spin only one way but not the Yuval Ne'eman, at Salam's other. Salam realized that a zero- suggestion, explored the implications mass neutrino could be a miniscule of group theory in particle physics, corkscrew, drilling its way through going on to arrive at parallel space at the speed of light. Travelling conclusions to those of Murray Gell- at this speed, no other particle could Mann's 'eightfold way'. Later, with overtake it, so there is no other Bob Delbourgo and John Strathdee, vantage point to view the neutrino's Salam explored how these internal spin. It would always appear to point particle symmetries could be welded the same way. A conventional right- with those of space-time. handed corkscrew looks left-handed The pinnacle of Salam's physics when reflected in a mirror, so a career came in 1979 when he shared neutrino reflected in a mirror would the Nobel Physics Prize with Sheldon no longer look like a neutrino - it Glashow and Steven Weinberg for would instead look like an their unification of electromagnetism antineutrino. Salam had realized that and the weak nuclear force in the the neutrino, Pauli's ghost particle, and tell him to think of something 'electroweak' theory, a word invented was the culprit which broke the mirror better'. Quashed, Salam hesitated by Salam in 1978. This unification of weak interactions. before submitting his massless was the outcome of an effort which The following morning, an elated neutrino idea for publication. Four had begun with Fermi but for Salam Salam bustled off the plane and months later, on 24 January 1957, had commenced with a 1958 paper rushed as fast as he could to his Pauli wrote again to Salam. Mrs. Wu with John Ward and which went on Cambridge office, where he & Co's result on the left-right to make Imperial College a focus for frantically calculated a few asymmetry in cobalt decay had been the study and applications of sponta consequences of his new theory. published, and independent neous symmetry breaking. In 1961-2, Even more elated by the way measurements had come in from Weinberg and Salam, collaborating everything seemed to be working out, Lederman and from Telegdi. Pauli at long range with Jeffrey Goldstone, he rushed onto a train to changed his mind and Salam's ideas confirmed the prediction that Birmingham, where Peierls lived, to had been vindicated. Meanwhile Lee massless 'Goldstone bosons' neces say he now had the answer to the and Yang in the United States and sarily accompanied conventional trick question posed a few years Lev Landau in Russia had arrived at spontaneous symmetry breaking. before. a similar conclusion about the A few years later, it was realized that Peierls' reply was typically kind but neutrino and its mirror reflection. these bosons do not apply to gauge firm. 1 do not believe left-right Soon after formulating his neutrino theories, and a new route was symmetry is violated in weak nuclear theory, at the tender age of 31, discovered, a route now known as forces at all.' With Mrs. Wu & Co. still Salam became Professor of the higgs mechanism, which led in assembling their epic experiment at Theoretical Physics at London's 1967 to the electroweak unification. Columbia University, Salam had prestigious Imperial College of As well as his physics research, knocked too early on Peierls' door. Science and Technology. With Salam worked tirelessly to further the But the young Pakistani was Salam's drive and ambition, Imperial cause of science in developing insistent, and gave his neutrino paper soon became one of the world's countries. Remembering vividly his to a physicist who was going to visit leading centres in field theory. own isolation when he had returned Pauli in Zurich. The reply soon came: As a researcher, Salam was always to his home country, in 1964 he 'Give my regards to my friend Salam where the action was. Not for him the founded the International Centre for
12 CERN Courier, January/February 1997 Physics monitor
Theoretical Physics in Trieste, Italy, to appreciate before his powers now a world-class research estab waned completely, in 1993 the centre lishment, where promising young organized a three-day physics A cold welcome scientists from all over the world get meeting which was attended by a taste of front-line research early in colleagues, admirers and former ryogenics is one of the big their careers. students from all over the world. One Ctechnological success stories of Salam's deceptively soft, husky was Frank Yang, whose talk on particle physics, and it was fitting that voice masked an iron will and mirror symmetry in 1956 had so CERN recently hosted an ruthless ambition. He could be much impressed the young Salam. International Symposium on arrogant, but also used argument as The culmination of the meeting was Cryogenics in Industry which a intellectual weapon to prise open a the award of an honorary degree of attracted specialists from all walks of difficult problem or seek new ideas. the University of St. Petersburg, cryogenics life. A consummate international, he was Russia. The rector of the University For particle physics, low equally at home with P.G. made the trip specially. Salam temperature equipment was first Wodehouse or the Koran. listened from his wheelchair but needed on a large scale for Luis Despite being the only Pakistani to could not speak. After the formal Alvarez' pioneer big liquid hydrogen have won a Nobel Prize, and despite ceremony, participants stood bubble chambers in the late 1950s. his impressive international patiently in line to offer their own For subsequent developments, achievements, Salam's position in his congratulations. There was little cryogenics has been frequently, but home country was ambivalent. Under response from Salam, but all hoped not always, synonymous with the the powerful rule of Ayub Khan, their message was getting across. improved performance provided by Salam once wielded considerable After famous names, it was the turn superconductivity, particularly the influence. However as a member of of younger students. One of the last high magnetic fields provided by the minority Ahmedi Islamic sect, he was a nervous young man from superconducting magnets. For resigned his influential position as Pakistan, a young researcher who bubble chambers, demand for chief scientific adviser in 1974 when had succeeded in gaining one of the cryogenic plant increased with the Pakistan's National Assembly under highly-prized scholarships to Salam's advent in the late 1960s of large Zulfikar Ali Bhutto excommunicated centre. As he bent towards Salam detectors equipped with the Ahmedis from Islam. The hunched in his wheelchair, he said superconducting magnets, where the Ahmedis claim that Mirza Ahmed, 'Sir, I am a student from Pakistan. born in Qadian in northern India in We are very proud of you.' Salam's the late 19th century, was the Mahdi, shoulders shook and tears ran down or Messiah, a view which is sacrilege his face. to conventional Islam. Mainly confined to Pakistan, India and East Africa, the small Ahmedi sect is a frequent target of intolerance and discrimination, both from the religious orthodoxy and the mass of people. In 1979, after the announcement of his Nobel award, Salam was initially invited to Pakistan by General Zia ul- Haq, but other pressures soon blew an icy wind of excommunication. With Salam stricken by illness, at Trieste it became clear he could not function much longer as the Large-scale cryogenics for CERN's LEP Institute's Director. As a tribute to its electron-positron collider - liquid helium founder, which he would be still able reservoirs from Russia.
CERN Courier, January/February 1997 13 Physics monitor
A cold welcome. At the opening of the recent International Symposium on Cryogenics in Industry at CERN: Organizing Committee Chairman Philippe Lebrun of CERN (left) with Bernard Hebral, Chairman of Commission A 1/2 of the International Institute of Refrigeration.
associated cryogenic plants will be capitalized for the LHC proton collider to be built in the LEP tunnel. Introducing the cryogenics confer ence proper, Oscar Barbalat of CERN looked at the impact of 'megascience' - as defined by the Organization for Economic Cooperation and Development - on cryogenics and applied superconductivity. While installations in many physics areas use 12-foot chamber at Argonne was savings in power - about 6 MW is cryogenics and superconductivity on subsequently upstaged by BEBC at needed to cool the 800 GeV HERA a large scale, Barbalat still saw the CERN and the 15-foot chamber at proton ring, while on average several move from megascience to industrial Fermilab. times this figure is needed to drive technology as a major obstacle. A new horizon opened with the the CERN SPS synchrotron at Jorg Schmid of CERN sketched the construction of Fermilab's Tevatron 450 GeV. use of cryogenics in particle with its four-mile ring of super While protons are heavy and 'stiff accelerators, both for bending and conducting magnets. proton beams need lots of bending focusing magnets and for the Superconducting magnets had been effort, electrons are very light and the radiofrequency accelerating cavities. used in beamlines, in low-beta beams pliable. However electron Giorgio Passardi of CERN outlined insertions to squeeze colliding beams lose a lot of energy due to the wide range of cryogenic options beams, and in spectrometers, while synchrotron radiation as they are now in use in detectors for particle research and development work had bent, so that electron rings are physics experiments. As well as the led to revolutionary new types of therefore are hungry for input power. advent and demise of the cryogenic filamentary conductors which went For protons, the superconducting bubble chamber, polarized target on to make a major impact on this spotlight falls on magnets to guide requirements had also helped to technology. But the Tevatron, with a the beams, while for electrons the introduce cryogenics to the particle thirst for 5000 litres of liquid helium superconducting goal is more on physics scene. For large detectors, per hour, blazed a new trail and was accelerating power. cryogenic requirements are centred the first industrial-scale cryoplant at a Development work to harness the around spectrometer magnets and particle physics laboratory. efficiency of superconductivity to calorimeter technology. Subsequently, the 6.3 kilometre drive radiofrequency cavities began One of the best known major HERA proton ring at DESY Hamburg at Stanford University (in the context cryogenic applications area for and the CEBAF recirculating linac of a linear accelerator) where physics is in the big push to control arrangement at the Jefferson electrons were first accelerated in a thermonuclear fusion, where Laboratory, Newport News, Virginia, superconducting resonator in 1965. superconductivity is indispensable for swelled the ranks of big By the 1980s cavities had been the next generation of containment superconducting magnet rings. installed at several electron machines. Bernard Turck of the Subsequently, the high magnetic machines and major programmes French Atomic Energy Commission's fields required for the new generation were underway at Cornell, CERN, Cadarache centre described the of colliders, such as RHIC at KEK (Japan), CEBAF/Jefferson.... French Toresupra, the German W7X Brookhaven and the LHC at CERN, To increase its energy, CERN's Stellarator and the ITER international can only be supplied by super 27-kilometre LEP electron-positron scheme, requiring respectively 35, 45 conducting magnets - conventional collider is being fitted with supercon and 1200 tonnes of superconductor. magnets being limited to fields of ducting accelerating cavities, a Another major outlet for about 2 tesla. In addition, scheme launched by the far-sighted superconducting magnets is for superconductivity gives considerable John Adams back in 1979, and the magnetic resonance imaging, mainly
14 CERN Courier, January/February 1997 Imperial College of Science Technology and Medicine, Department of Physics, Powered Crates South Kensington, London SW7 Further to all our CERN approved CERN-Spec. Crates NIM-, CAMAC-, FAST BUS-, VMEbus 422/430 Wes-Crates supplies other Crates based upon these Systems. Two post doctoral Research Associates
Applications are invited for two PPARC-funded two year posts to join the UK collaboration searching for the direct signatures of the dark matter of the Universe, in the form of new, Weakly Interacting Massive Particles (WIMPS). The experiments are being deployed in the Boulby mine, N. Yorkshire and the posts are both connected with the development of liquid Xe scintillation detectors to achieve higher sensitivity to dark matter signals. Post 1 is to be initially at ICSTM with visits to Boulby envisaged later. The post holder will assist in the building and commissioning of prototype Xe chambers. Knowledge of cryogenic and/or nuclear counting techniques is desirable. Post 2 is to be mainly located at the Rutherford Appleton Laboratory, near Oxford but in close collaboration with ICSTM and also involving experimental work at Boulby Mine. It will involve design and production of a background veto VMEbus-crate VME64 9U x 400 mm system and other design and analysis work related to the Xenon according to the recommendation of VIPA experiment. Experience in both particle counting techniques and computer skills are required. The candidates will join an established team and there are reasonable prospects of extension of the posts beyond the two years. Salary in the PPARC 1A range. Closing date, March 15. Posts available from April/May, 1997. Send CVs and the names of two referees or requests for further details to Dr W.G. Jones tel. 0171 594 7805 or Dr J.J. Quenby tel. 0171 594 7527 Department of Physics, ICSTM, Prince Consort Rd. London SW7 2BZ, UK.
VMEbus-crate CERN-spec. V430 Max-Planck-lnstitut fur Kernphysik Postfach 103980, D-69029 Heidelberg
The Max-Planck-Institute in Heidelberg, offers a Postdoctoral Position for the project HERA-B in the group of Prof. Dr. W. Hofmann. The goal of the HERA-B experiment is the first observation of CP-violation in decays of B-mesons. The MPI Heidelberg is involved in the construction of the silicon vertex detector, which is placed inside a vacuum tank in order to achieve the best possible resolution for secondary vertices. The VMEbus-crate CERN-spec. V422 successful candidate will participate in the construction and comissioning of the vertex detector and in the analysis of the HERA-B data. Every CERN-Spec. so far Crates and Power Supplies from has given rise to a CERN- WES-Crates are flexible because The applicant should have a university degree with a approved Crate from: of modular systems. Ph.D. in experimental high energy physics, hardware experience as well as knowledge in on-line computing, data analysis and Monte-Carlo simulation. The position will be free from May 1st, 1997. The LJES -Crates Wes-Crates GmbH Telefon 0461 - 77 41 77 contract will initially be for 2 years, with possible Pattburger Bogen 33 Telefax 0461 - 77 41 41 extension to 5 years, and a salary according to BAT D-24955 Harrislee/Flensburg International +49 461 Ha. Handicapped applicants will be given preference to Germany Your contact in Geneva: HiTech Systems Sa, Abenue Wendt 16, others with the same qualification. Applications should 1203 Geneva, Tel.: 022/344 7788, Fax: 022/45 6551 be sent under Reference 03/1997 to Max-Planck-lnstitut Your contact at PSI and ETH Zurich: Dipl.-lng. Kramert AG, fur Kernphysik, Personalverwaltung, Postfach 103980, Villigerstr. 370, CH-5236 Remigen, Tel.: 056/441555, Fax: 445055 D-69029 Heidelberg. E-mail: [email protected]
CERN Courier, January/February 1997 15 Physics monitor
Generic prototype of a scintillating-fibre detector for the DIRAC pionic atom experiment at CERN. The design uses a modular position- sensitive photomultiplier (PSPM) housing structure accommodating 48 channels. As well as making for flexibility in the final size of the full detector, this also allows a rapid repair or exchange of defective modules or PSPMs..
for medical tomography, where David Hawksworth of Oxford Magnet Technology pointed out that since the introduction of this technology in the early 1980s, the market has grown to some 12,000 installations worldwide. For the future, Rene Fluckiger of Geneva described the impact of new superconductors. Summarizing the status of particle physics at the meeting, Pierre Darriulat of CERN drew attention to the need for low temperature detectors, especially in spaceborne experiments, to make precision measurements. As well as these major scientific but also a simple and reliable means LAPP(Annecy)/CERN/ IHEP/Kyoto- areas, more specific projects were of handling the position information in Sangyo/Trieste/UOEH/Waseda team. covered in brief oral presentations real time. It is based on a new series of PSPM, and poster sessions, while the To meet this demand, a scintillating- H6568 from Hamamatsu Photonics, parallel industrial exhibition attracted fibre detector is in preparation for the followed by specially designed front- considerable interest. But the real 'DIRAC (Dlmeson Relativistic Atom end electronics and a peak-sensing star of the show was CERN's own Complex) experiment at CERN's circuit (PSC), which digitizes the installations, cryogenic and proton synchrotron based on the track position in real time by otherwise. The delegate tours of the technical achievements of RD17 suppressing annoying cross-talk Delphi experiment at the LEP, research and development project - between adjacent channels. electron-positron collider, the fast readout of scintillating fibres With an array of 0.5 mm diameter superconducting magnet and cavity using position-sensitive fibres, the space resolution for test area and the central cryolab photomultipliers (PSPM). The individual minimum ionizing particle were fully booked. technique fully profits from the 'hits' is about 130 micron with a advantages photomultiplier detection efficiency higher than 95 %. technology developed over the last Double tracks were also detected several decades. with a minimum two-hit separation of The unusual DIRAC experiment about 0.4 mm. As required for the DETECTORS sets out to measure pion-pion DIRAC experiment, the distance scattering by synthesizing atoms between two tracks was successfully Scintillating fibres at consisting of a positive and a digitized in real time with a simple work (1) negative pion rotating round each logic circuit. The time jitter of signals other. Precision measurements of the through the electronics (PSPM + lifetime of these atoms will reveal PSC) was less than 500 ps. A finer or o help in the search for rarer new information on pion-pion coarser granularity of detector Tphysics events, one emerging interaction, vital to test emerging elements could be achieved by using trend is to pull together more precise ideas in quark-gluon field theory fibres of appropriate diameter without information on the pattern of (quantum chromodynamics - QCD). any major modification of the present produced particles early in the event For the experiment, a generic setup. selection process. This requires a prototype with 96 channels, With proven photomultiplier detector which assures not only good corresponding to a fifth of the full technology, such a device could have space and time resolution while detector, has recently been produced a wide range of ongoing applications acting as such a topological trigger, and successfully tested by a for high-luminosity experiments.
16 CERN Courier, January/February 1997 Physics monitor
A two-dimensional image of particle hits Spinning summary. Phil Ratcliffe (Como) passing through a beam counter provided with wraps up the 12th International Symposium on a mask in the form of tiny pieces of scintillator High Energy Spin Physics, held in Amsterdam. in the shape of letters. Such fine pixel granularity of 0.43 x 0.43 mm2 is difficult to achieve using conventional photomultipliers.
Spin physics
symposium Hiif USUAL. I •
ummarizing the 12th S International Symposium on High Energy Spin Physics, held in Amsterdam from 10-14 September, Phil Ratcliffe (Como) said that spin physics has now definitely come of age. This is evident from the wealth of experimental and theoretical Channel number m Layer I {1 dh0.43 mm) results - accurate determination of structure functions, accurate electroweak measurements and sophisticated calculations within the framework of perturbative Quantum Scintillating fibres at Chromodynamics (QCD). Tremendous progress was also work (2) reported in the polarization of beams the remaining spin must be due to and targets. the gluons which hold the proton The meeting's 300 participants together, and to angular momentum In another development for a were welcomed by incoming of quarks and gluons. position-sensitive photon detector chairman of the International John Collins (Penn State) gave a using scintillating fibres, the RD7 Committee on High Energy Spin broader discussion of mostly research and development Physics, Charles Prescott of SLAC, theoretical aspects of violent collaboration at CERN has who takes over from Brookhaven's scattering within the context of QCD. produced an imaging silicon pixel Alan Krisch. John Ellis of CERN set He emphasized that while a great array tube, in which the phosphor the tone of the conference with a deal is now understood about the screen of a conventional image discussion of the spin aspects of hard-scattering parts (treated with intensifier is replaced by a multi- violent scattering, where a projectile perturbative methods), ways for anode chip (developed in turn by penetrates deep inside a target understanding the non-perturbative the RD-19 group). This technique nucleon. Ellis paid particular attention (soft) parts are still urgently needed. sidesteps the degradation usually to the momentum distributions Gerd Mallot (CERN) and Stefano associated with using image (structure functions) of constituents Forte (Torino) gave respectively intensifiers to read out with different spin polarizations inside experimental and theoretical scintillating fibres. Another team, the proton. overviews of the spin structure RD-46, is investigating the In 1987, the European Muon function for protons and neutrons. potential of arrays of 20 micron Collaboration at CERN found that the Polarized scattering data are capillaries filled with liquid proton's spin is not all accounted for becoming very precise and cover an scintillator. The biggest ongoing by the individual angular momentum interesting kinematic range. application remains the and individual spins of the quarks, One important sum rule due to scintillating fibre tracker of the and a large fraction must be due to Bjorken relates the difference Chorus neutrino experiment at something else (see page 3). Since between the proton and neutron CERN, containing in total some then, measurements have shown structure functions to basic weak 2,600 kilometres of fibre. that only about 25% of the proton's interaction parameters obtained from spin is carried by quarks, and neutron (beta) decay. With this physicists now believe that much of fundamental relation now verified to a
CERN Courier, January/February 1997 17 Physics monitor
Chairman of the spin symposium organizing committee Kees de Jager (right) with new chairman of the International Committee on High Energy Spin Physics Charles Prescott of SLAC (centre) and outgoing president Alan Krisch of Brookhaven.
few percent, it is customary to impose the relation and extract other quantities, such as a value for the strong coupling constant that is remarkably competitive with other measurements. Studies of the behaviour of the structure functions at small momentum fraction (x) will help to disentangle subtle effects. Two years ago, at the 11th symposium in Bloomington, the general view was that quarks contribute about one third that of the photon, can also be used presented by Richard Prepost (Wis of the proton spin, while now the first to investigate the spin of the nucleon. consin), who emphasised the polari indirect evidence for gluon Betsy Beise (Maryland) indicated zation role of the machine. Measure contributions is becoming evident. how experiments at moderate ments of lepton asymmetries Several other talks discussed energies (e.g., SAMPLE at MIT/ contribute decisively to an increased experiments to directly measure this Bates) provide the first indications for precision in the determination of the effect, including forthcoming studies a small and positive strange quark vital electroweak mixing parameter. at Brookhaven and at CERN contribution to the magnetic moment Prepost also discussed the impor (COMPASS experiment). of the nucleon. Theoretically the tance of Cherenkov Ring Imaging The large gluon contribution to the estimates for this contribution, though Detectors in heavy quark measure proton spin must be accompanied by widely varying, are generally ments. orbital angular momentum of quarks negative. Steve Vigdor (Indiana) summarized and gluons. Xiangdong Ji (MIT/ Desmond Barber (DESY) described possible tests of symmetry principles Maryland) gave an enthusiastic and progress with polarized beams, in medium-energy hadron physics, clear account of how to handle quark where in the future 80% polarized including violation of time reversal orbital angular momentum. positron beams may be possible at symmetry in an experiment under Another subject of great interest HERA. An example demonstrating consideration at COSY in Julich, or was single-spin asymmetries, notably the day-to-day importance of spin is charge symmetry breaking effects in those in hadron production in proton- the use of polarized beams at LEP, nuclear forces. Jo van den Brand proton collisions. Ken Heller providing precision energy (Amsterdam) discussed how (Minnesota) reviewed the production calibration. dedicated experiments can address of hyperons, in which the Yousef Makdisi (Brookhaven) and questions such as the role of asymmetries display many regular Hideto En'yo (Kyoto) described relativistic corrections and three-body features in their kinematic developments at Brookhaven's RHIC forces in the quantum mechanical dependence, but with some puzzling heavy ion collider (March 1996, page description of light nuclei. exceptions. A related quantity is the 19), indicating the possibilities of The meeting drew 300 participants, sizable left-right asymmetry in pions measuring such quantities as the with 15 plenary presentations and 5 produced in polarized proton-proton gluon polarization in the proton and rapporteur talks of workshops scattering. the separation of the various different sponsored by the International The use of weak interactions in the quark contributions, stressing the Committee on High Energy Spin search for physics beyond the complementarity to experiments Physics. In addition, there were Standard Model was discussed by using electron beams at CERN, about 150 contributions to the Mike Musolf (Seattle). The weak SLAC (Stanford), HERA (DESY, afternoon parallel sessions, covering interactions, in particular the different Hamburg) and CEBAF (Newport aspects of both nuclear and particle couplings to left-handed and right- News, Virginia). physics. Round-table discussions, handed quarks, and the difference Results of the SLD experiment at were organized by Yuri Arestov between the coupling to quarks and Stanford's SLC linear collider were (Moscow) on RAMPEX, a new spin
18 CERN Courier, January/February 1997 Physics monitor
Display of a candidate diffractively produced "towers" whose height is proportional to the W-boson in the CDF experiment at Fermilab's transverse energy deposited. This event shows Tevatron proton-antiproton collider. Such Ws one tower with electromagnetic energy deposit are produced by quark-antiquark annihilation of 42 GeV with no detected balancing particles, and subsequently produce an electron and an a clear sign of a W-boson (the accompanying undetectable neutrino. In this case, the neutrino cannot be detected). Three units of antiquark comes from a pomeron rather than pseudorapidity, from -1.2 to -4.2, are seen to the antiproton. be empty, and other detectors (not shown) The calorimeter measures energy in cells of extend this "rapidity gap" to -5.9. A quasi- azimuth angle and pseudorapidity (a measure elastically scattered 'spectator' antiproton was of the polar angle). Hit cells are plotted as detected at a pseudorapidity of -7 units. experiment with 70 GeV protons at the Russian IHEP centre at Serpukhov, near Moscow, and another by Vernon Hughes (Yale) on the gluon spin distribution. The next symposium in the series will be held in Protvino (Russia) in September 1998.
From Piet Mulders
Gaps in understanding
espite the unlikely title of Small- Dx and Diffractive Physics, a four- QCD calculations in certain special the two-gluon pomeron called the day workshop sponsored by Argonne circumstances, typically when BFKL pomeron after the initials of its National Laboratory and Fermilab masses or the momentum four main originators (Balitsky/Fadin/ recently held at Argonne focused exchanged in a reaction are large. Kuraev/Lipatov). attention on the understanding of the In practically all the interactions that The pomeron is rather special in strong inter-quark force, and in occur at Fermilab's Tevatron proton- that is has the same quantum particular its vacuum structure. antiproton collider this is not the numbers as the vacuum (apart from The elegant theory of the inter- case, and we are unable to calculate its spin which is a complex issue). quark force, called Quantum with QCD the probabilities for What is the relation between the Chromodynamics or QCD, is in many common reactions, such as elastic pomeron and the vacuum? Both ways similar to electromagnetism, scattering where the proton and might be considered as nothing - the but with essential differences which antiproton simply emerge deflected. ultimate in simplicity, but from ensure that quarks remain In this simplest case some another point of view the ultimate in permanently bound inside their momentum is transferred from one continuously variable quantum parent nucleons and do not emerge beam particle to the other, and complexity, seething with fluctuations as free particles. The messengers of whatever carried the momentum as particle-antiparticle pairs of all the inter-quark force are gluons, must have been colourless (or the types (electrons, quarks, gluons, etc.) which carry 'colour', analogous but protons could not have remained so). are created and annihilated. These very different to the familiar electric The most likely suspect, proposed transient particles are hard to detect, charge of electromagnetism. In in 1975, is a colourless two-gluon but their effects do show up in some particular the visible particles, such composite. Before the gluon era, this experiments. A vacuum is definitely as protons or neutrons, have no net is what had been traditionally called not "nothing". colour - are 'colourless' - and this the "pomeron", after the Russian Moving from the complexity of simple requirement underlies the physicist Isaak Jakoblevich nothing to that of a physical particle, observed gamut of different particle Pomeranchuk. However in QCD it its constituent quarks and gluons states. does not make sense to say that the themselves hardly have any well Hundreds of tests of QCD have pomeron is exactly two gluons, defined identity. They are continually been made and it has never yet been because the gluons will be changing colour, emitting and found wanting, so we have come to exchanging more gluons between absorbing gluons; gluons can meta believe that it is THE theory of strong themselves as well as virtual quark- morphose into a quark-antiquark pair, interactions. However we only know antiquark pairs. Such effects are antiquarks can annihilate with quarks how to make reasonably accurate incorporated in a modern version of to make gluons, etc.
CERN Courier, January/February 1997 19 Physics monitor
The "inside" of protons and all other from pomeron exchange, which cuts charge. However by measuring the strongly interacting particles is an otherwise uniformly populated pomeron quarks and observing how continually boiling with activity, like angular region into distinct zones. their distributions change with photon the surrounding vacuum. Another The rapidity gap can be between the wavelength one can infer the degree of complexity is exemplified two jets, in which case the pomeron pomeron's distribution of gluons. by the maxim "the harder you look, carries a very large momentum A remarkable, and still perhaps the more you see". This means that transfer, or to one side. In the latter controversial, result from H1 was as the proton is probed with photons case it seems that the scattering their conclusion that at "long" of ever decreasing wavelength, an quark or gluon comes from the wavelengths (Q2 = 5 GeV2 for initial fuzzy blob gradually resolves pomeron, and by measuring the jets experts) the pomeron seems to be into three quarks, which then one can probe the constituent mostly a single gluon! As the dissolve into more and more quarks, structure of the pomeron. wavelength decreases this "evolves" antiquarks and gluons. The first data on jets produced in by emitting other gluons and quarks If the proton is moving with a pomeron interactions came from into more constituents with a more momentum p, these "constituents" Experiment UA8 at the CERN proton- democratic distribution of momenta. each have momenta xp, so that the antiproton collider (March 1992, page While in certain circumstances the sum of all the momentum fractions x 4). CDF also has evidence for W- pomeron seems to behave equals 1. For small probe bosons produced in this way, where dynamically like a single gluon, we wavelengths, with high resolving one beam particle scatters almost know that cannot be the whole story power, we see a rapidly increasing elastically and the accompanying because the gluon carries colour and density of gluons as x gets very pomeron interacts with the other the pomeron has to be colourless. small, less than 0.0001. Such an particle to make a high mass state. We are led to suppose that the gluon increase cannot continue indefinitely. Comparing W and jet production colour is compensated by something Presumably this low-x gluon cloud reveals the fraction of gluons and "soft", e.g. that the pomeron, at short will ultimately become so dense that quarks in the pomeron. wavelengths, is one gluon carrying pairs of gluons will start recombining, Experiments UA1 and UA8 at the most of the pomeron's momentum as if a branching tree were to CERN Collider and now CDF and and another one or two gluons develop a surrounding net where the DO at the Tevatron have evidence for carrying very little. As the wavelength densely packed twigs fuse together. jet production with two forward decreases (better resolving power) The higher gluon density at low x is rapidity gaps, interpreted as the pomeron becomes a more intimately related to the pomeron and pomerons colliding, with the pomeron democratic mixture of gluons and in turn to the rise of particle constituents supplying the jets. quarks, sharing the momentum more interaction probabilities with energy. The experiments at HERA, ZEUS equally. The experimental study of the and Ht, are complementary, colliding This seems to fit the observations, pomeron took an important upturn in electrons and protons. The electrons although a lot more data are needed the last three years with experiments radiate photons which probe the to be sure. This picture of the at the Tevatron and at DESY's HERA proton with wavelengths much pomeron raises some very electron-proton collider. At the smaller than the proton size. Some interesting theoretical issues which Tevatron's CDF and DO experiments, 10% of their events have the proton may have profound consequences the main progress has been through emerging almost elastically, and for our understanding of the strong studies of two closely collimated these can be interpreted as the force. Much more work, theoretical sprays or 'jets' carrying high proton emitting a pomeron; this as well as experimental, is needed transverse energy, known to result pomeron is then probed by the before we know whether these ideas from hard quark or gluon scattering, electrons' photons. are correct. One conclusion was accompanied by what are call Being an electromagnetic quantum, however clear: this field is now very 'rapidity gaps'. the photon probes directly the active, with exciting new data from Rapidity gaps are large angular charged constituents of the pomeron, the Tevatron and HERA and much regions where no particles are and is blind to the strongly-interacting theoretical progress. We do not yet produced, and are known to result gluons which have no electric have a coherent picture of the
20 CERN Courier, January/February 1997 Physics monitor
pomeron which describes all the data photons, Ws, Zs and gluons - move October examined the SUSY discov and makes testable predictions, but a the chessmen around on the board. ery potential of the experiments at better understanding of this vital Quarks and leptons are 'fermions', CERN's new LHC proton-proton aspect of 'nothing' remains a major obeying the Pauli Exclusion Principle, collider. The conclusion was that goal. so that not more than one particle LHC could find SUSY up to some can occupy any one square on the 400 GeV for sleptons, some 2000 From Michael Albrow and Alan White quantum chessboard. On the other GeV for squarks and gluinos, and hand the messenger particles are probe the lightest supersymmetric 'bosons' and have no such quantum particles up to some 350 GeV, Desperately seeking accommodation restrictions. covering almost the full allowed SUSY demands that for every range. Despite the cluttered condi unseen SUSY known particle, there is a tions of 14 TeV proton-proton colli supersymmetric partner - each sions, the expected SUSY signals or twenty years, SUSY - or fermion has a boson 'spartner', and should be visible. The experimen Fsupersymmetry - has been the vice versa. Quarks pair with talists are convinced that if SUSY is heartthrob of theoretical physicists. 'squarks', and leptons with 'sleptons', not just a dream, then the LHC will The widespread conviction that while the Standard Model bosons reveal all. SUSY will solve many of their pair with 'charginos' and 'neutralinos'. problems has spilled over into the SUSY's appeal is so compelling that experimental sector, but despite some enthusiasts have repackaged hunting high and low, no sign of the Standard Model accordingly. SUSY has been seen. The lightest (and most stable) of FERMILAB Strictly speaking, SUSY is no these additional SUSY particles also Standard Model. Today's Standard provide a potential source of 'dark First antihydrogen Model takes the electroweak picture, matter' - the invisible material which unifying electromagnetism and the we nevertheless know must be there xperimenters at Fermilab have weak nuclear force, in tandem with to account for the observed motion of Eproduced and detected atoms of the field theory of quarks and gluons galaxies. Is this intangible dark antihydrogen using a gas-jet target in (quantum chromodynamics - QCD). matter the same as the unseen the Antiproton Accumulator. This This shotgun wedding between the SUSY? confirms results announced last year electroweak picture and QCD has With the spectrum of unification (March 1996, page 1) at CERN. never been comfortable, but a better mass scales so large, SUSY particles Both the CERN and Fermilab match requires a considerable dowry can sit anywhere in a mass ladder antihydrogen experiments used an in the form of a unification scale of extending anywhere from some 50 to idea proposed by Charles Munger, some 1015 GeV, very different to the 1000 GeV (the heaviest known Ivan Schmidt, and Stanley Brodsky in 100 GeV or so of the electroweak particle, the top quark, has a mass of 1992. A fast-moving antiproton picture, itself a major step from the some 175 GeV). These masses passing an atomic nucleus can zero mass photon. extend beyond the scale currently create an electron-positron pair; in What is behind this immense accessible to laboratory experiments. rare instances, the positron will stick staggering of mass scales from one However experiments at CERN's LEP to the moving antiproton to make an unification to the next? The hope is electron-positron collider and atom of antihydrogen. Fermilab's that SUSY can bridge these mass Fermilab's Tevatron proton-antiproton higher-intensity and higher-energy chasms and make the successive collider have explored the lower antiproton source open up higher unification pictures more assimilable. energy fringe of the available SUSY antihydrogen yields. But the price is a doubling of the territory. At LEP, one SUSY sector A key to the success of these number of particles. has been ruled out below 80 GeV, experiments is the gas-jet target, The chessmen of particle physics while at the Tevatron another sector is using a design developed by Mario come in two kinds, the quarks and excluded below about 200 GeV. Macri and Mauro Marinelli at Genoa leptons. 'Messenger particles' - A special meeting at CERN on 30 University and INFN.
CERN Courier, January/February 1997 21 The CPLEAR experiment at CERN's Low Energy Antiproton Ring, LEAR, has just Matter symmetry completed its final run.
Each of C, P, and T was once thought to be conserved in all interactions. We now know this is The delicate violation of VP not the case. In fact non- symmetry' - changing particles to conservation of the CP combination antiparticles and reflection in could help to explain why there are three-dimensional space - three families of particles, and why appears to play a fundamental there is any matter in the Universe to role in the order of things. Thirty make stars, planets, and human years after its discovery, it is still beings. On a more esoteric level, not understood. despite the observed CP violation, current theory demands that the CPT combination be conserved. Any hint of CPT violation would send particle theorists back to the drawing board. Looking-glass particles CPT conservation implies that T must be violated to cancel out CP n any recipe for particle violation. In other words, an I interactions, take a particle, replace antiparticle is indistinguishable from a it with its antiparticle, look at it in the particle moving backwards in time. mirror, and reverse its direction in In the electromagnetic and strong is violated in neutral kaon decays at time. The result, according to the interactions, each of C, P, and T the level of a fraction of a percent. famous CPT symmetry theorem, appears to be conserved, and this In 1973, after Nicola Cabibbo had should be indistinguishable from the was once believed to be true for the described how to look at weak original. This apparently abstract weak interaction as well. However, decays of the kaon, Makoto idea has profound philosophical and the world of physics was startled in Kobayashi and Toshihide Maskawa down-to-earth implications which the 1956 when T. D. Lee and C. N. Yang showed how CP violation could be CPLEAR experiment at CERN's Low concluded from a survey of available accommodated in the Standard Energy Antiproton Ring, LEAR, has data that P might not be conserved in Model by increasing the number of been probing for a decade. After weak interactions. They based their particle families from the two known using an impressive 1013antiprotons, conclusion largely on the fact that ones to three or more. This idea the experiment has just completed its particles called kaons had been began to look very attractive with the final run. observed to decay into two different discovery of the bottom quark, final states which have opposite lightest member of a third quark parities. family, by Leon Lederman's group at C, P, and T Nor does the weak interaction Fermilab near Chicago in 1977. Ever conserve C. The weakly interacting since, the quest has been on to C, P, and T are vital test neutrino spins left-handedly, and the measure CP violation in the kaon symmetries of particle interactions. operation of charge conjugation system precisely. C, charge conjugation, represents would produce a left-handed replacing a particle by its antimatter antineutrino, a particle which does counterpart. P, parity, corresponds not exist in nature's kit of parts. The Brief history of universe to looking in a mirror which reverses combination of C and P, however, not just one but all three spatial co produces a right-handed antineutrino, The reason for all the excitement ordinates, and T is time reversal. If a which does exist. Physicists hoped about CP violation goes back to the symmetry does not effect the that the CP combination would be Big Bang itself. Matter and outcome of an interaction, then that conserved in weak interactions, but antimatter are believed to have been interaction is said to conserve the in 1964, James Cronin and Val Fitch created in equal amounts, but today symmetry. demonstrated at Brookhaven that CP there appears to be only matter.
22 CERN Courier, January/February 1997 Matter symmetry
Measurements of the mass difference between *psw long lived and short lived kaons and the CP- violating phase angle are dominated by CPLEAR results (dark area), and agree precisely with the theoretical prediction.
decay, such as into a three pion system which is in the same CP- condition as the initial kaon. Consequently, this state lives longer
and is known as K-long, KL, the other
being called K-short, Ks. The Cronin and Fitch experiment demonstrated
that about one in 500 KL decays produces just two pions, violating CP. In the 1980s, CERN experiment NA31, and Fermilab's E731 and later rates of KL and Ks into neutral and Science fiction is fond of anti-worlds, must be some fundamental differ charged pion pairs. This whose inhabitants seem identical to ence in the way nature treats matter measurement is extremely sensitive the inhabitants of ordinary matter and antimatter. to CP, and since CP violation is a worlds. There is a perfect symmetry Sacharov's third condition requires subtle effect, it is also extremely between the two, and when anti-man the CP combination to be inexact, as small and difficult to measure. meets ordinary man, the two demonstrated by Cronin and Fitch. However, an accurate measurement annihilate leaving behind nothing but This is because if CP symmetry were would show if the Cabibbo - energy, largely in the form of exact, then the matter-to-antimatter Kobayashi - Maskawa mechanism photons. If this scenario were really asymmetry would precisely cancel provides for enough CP violation in true, then all the matter and the antimatter-to-matter asymmetry. the Standard Model to account for antimatter created at the Big Bang the observed matter antimatter should have disappeared in this way, imbalance, or if some other effect is leaving behind a Universe full of The neutral kaon system at work. So the stakes are high. photons. Clearly this is not the case, NA31 and the two Fermilab but it is very nearly true. There are Apart from the matter-antimatter experiments slowly converged on about a billion photons in the imbalance of the Universe, neutral compatible results, but the results Universe for every proton, or put kaons provide the only evidence yet remained inconclusive. New another way, nature's interactions seen for CP violation. The electric experiments, NA48 at CERN have curiously allowed one proton to dipole moment of the neutron is also (October 1995, page 16) and KTeV survive for every billion to have believed to depend slightly on CP at Fermilab (November/December annihilated with antiprotons. violation, but experiments are not yet 1996, page 5), are now taking data In 1966, the Russian physicist sensitive enough to measure this which will repeat the measurements Andrei Sacharov defined three effect. of their predecessors with ten times conditions necessary for this Neutral kaons and antikaons are greater precision. imbalance to arise. The first says strange particles, not simply because CPLEAR, in the meantime, has had that protons can not be absolutely they contain a strange quark or other priorities. The experiment has stable, they must decay with a antiquark, but because each is made concentrated more on CPT than CP, lifetime which he estimated to be up of a quantum superposition of two and has measured CPT and T about 1055 years. This means that states. One of these can decay into symmetries individually as well as for all the protons in the Earth, fewer a pair of pions with no violation of looking at CP violation. than a bread crumb's worth should CP. The other, however, cannot, have decayed so far. The second since the two pion system is in a requires the Universe to have passed different condition with respect to CP The CPLEAR experiment through a period of thermal than the initial kaon. This state disequilibrium, and the third brings us therefore has to find more CPLEAR's neutral kaons and to CP violation. It states that there complicated CP-conserving ways to antikaons are produced when CERN Courier, January/February 1997 23 Matter symmetry antiprotons from LEAR annihilate kaons and antikaons from which with protons in a hydrogen target. CPLEAR has measured a CPT DESY Theory Four times out of a thousand, these violating parameter which is also annihilations produce a neutral kaon consistent with no CPT violation. Workshop or antikaon along with a charged kaon and a pion. The charged kaon iscrete symmetries - the is detected and identifies what sort of So what? Dbehaviour of particle interactions neutral particle is produced. under distinct 'reflection' operations - Negative kaons are produced along But what of the philosophical and could play an important role in a with neutral kaons, positive ones with down-to-earth implications mentioned deeper understanding of the nature neutral antikaons. It is this ability of earlier? The Standard Model can at both very small and large CPLEAR to identify the initial particle accommodate CP violation, but it distances and provided the focus for which is the experiment's strong doesn't explain it, nor does it say how the recent Theory Workshop at the point. much of it there should be. All the DESY Laboratory in Hamburg. For the measurement of CP Standard Model says is that CP Special attention was paid to the violation, once the initial neutral violation is possible as long as there violation of CP symmetry (see particle has been identified, CPLEAR are at least three families of matter previous article). In the Standard measures the time dependence of its particles. Measurements at CERN's Model of particle physics, CP decay rate to two charged pions. Large Electron Positron collider, LEP, violation is attributed to a relative Neutral kaons and antikaons are and the Stanford Linear Collider, phase in the three-dimensional SLC, in California indicate that there made up of different amounts of KL (Cabibbo-Kobayashi-Maskawa - and Ks, so the time evolution of their are precisely three families, just the decay curves is different and there is number required, no more, no less. an interference effect between the Furthermore, for the time being at two. This allows an accurate least, theoreticians can sleep measurement to be made of the peacefully at night, since CPT does phenomenon since without CP appear to be conserved. And as for violation there would be no the down-to-earth, without CP- interference. violation, we simply wouldn't be here, CPLEAR's measurement is in good and you don't get much more down- agreement with theory, but pleasing to-earth than that. as this is, it does not in itself rule out significant CPT violation. This is By James Gillies because the measurement could mask a number of different CPT violating effects which cancel each other out. In order to make an unambiguous measurement, CPT must be measured directly, and this is where CPLEAR is unique. The electron and positron producing decays of neutral kaons are sensitive to T violation, and CPLEAR measures a T-violating parameter which is of the right magnitude to Quark mechanisms contributing to violation of compensate the measured CP CP symmetry: top, the 'box' diagram gives violation exactly, leaving CPT 'indirect' CP violation, while below, a so-called 'penguin' diagram gives 'direct' CP violation. symmetry intact. Similarly, there are Because the sixth ('top' -1) quark is so heavy, also CPT sensitive decays of neutral its contribution dominates. 24 CERN Courier, January/February 1997 Matter symmetry Incongruous penguins. As birds, they are confined to the Southern Hemisphere. In physics, penguin mechanisms make for CP violation. Andrzej Buras (left), Chairman of the recent DESY Theory Workshop and John Ellis of CERN, with a penguin of the physics kind. able to measure it in the first years of the next millennium. Similarly the very rare decay of the long-lived neutral kaon into a neutral pion and an electron-positron pair searched for at Fermilab (November 1996, page 5) should give important insight into direct CP violation. While the CP violation has been observed so far only in kaon decays, where the effects are rather small, CKM) matrix which parametrizes of CP violation parameters. While the much larger effects are predicted for quark transitions under the weak indirect CP violation in the Standard B mesons (containing the beauty nuclear force (mediated by heavy Model is consistent with experimental quark). As stressed by Robert charged W bosons). data, strong cancellation effects Fleischer (Karlsruhe) there are The original effect seen in the between various penguin diagrams several decays where measurements decays of long-lived neutral kaons for the top quark mass of order 175 should fix CP-violating phases into two pions in 1964 is attributed to GeV and large hadronic uncertainties without any hadronic uncertainties. Indirect' CP violation through the preclude a precise prediction for the The large variety of CP-violating mixing of the neutral kaon and its 8 ratio at present. asymmetries in B-decays should antiparticle and described by a box The experimental situation on this allow for decisive tests of the diagram (see top figure). This type of ratio is still uncertain, with minimal Standard Model and possibly signal violation is usually characterized by a overlap between the results of the some new physics beyond it. small parameter s, measured to be NA31 collaboration at CERN and Thus CP violation in B-decays is the roughly 2.3 x 103. E731 at Fermilab. Most theoretical main goal of B-factories at SLAC However the Standard Model also estimates favour the lower Fermilab (Stanford) and KEK (Japan) and of allows 'direct' CP violation, value, although due to hadronic the dedicated HERA-B experiment at characterized by a parameter e', uncertainties the CERN result cannot DESY in Hamburg which will all governed by the so-called "penguin" be excluded by the Standard Model. begin operation in a few years. diagrams with internal exchanges of Within several years the Useful CP-violation studies in B- the sixth 'top' quark (see lower figure experimental situation should be decays should also come from CESR on page 24). clarified through improved at Cornell and from Fermilab's Because of the contributions of the measurements at CERN and Tevatron. High precision top quark to the mechanisms, both Fermilab and by the KLOE measurements of CP-asymmetries in these CP violation parameters are experiment at DAFNE in Frascati. B-decays are expected from a sensitive to that quark's mass. As It is important to study other CP dedicated experiment at CERN's summarized by Ahmed AN (DESY) violating decays which are LHC. A review was presented by the most recent measurements of the theoretically cleaner. As stressed by Walter Schmidt-Parzefall (Hamburg). CDF and DO collaborations at Buchalla, a "gold plated" decay in this According to the Standard Model, Fermilab give a rather precise value respect is that of the long-lived kaon CP violation outside the K-meson of the top quark mass (175 ± 6 GeV) into a neutral pion, neutrino and and B-meson systems is expected to allowing improved predictions for CP antineutrino, proceeding almost be essentially unobservable. On the violation. exclusively through direct CP other hand, as reviewed by Werner The theoretical status of 8 and of violation. The predicted branching Bernreuther (Aachen), new sources the ratio e/e' was summarized by ratio (3 x 1011) and the presence of of CP-violation, present in multi- Gerhard Buchalla (Fermilab). Refined neutrinos and the neutral pion make Higgs models or models with gluon corrections and the more the measurement of this decay supersymmetry could give rise to accurate top quark mass have both formidable. Yet a newly approved measurable effects. considerably improved the evaluation experiment at Brookhaven should be Extensions of the Standard Model CERN Courier, January/February 1997 25 Matter symmetry predict new CP-violating interactions atoms and tests to be performed at The baryon asymmetry in the for quarks and for leptons. Attempts DAFNE. Universe (matter-antimatter asymme to trace such interactions include a Graham Ross (Oxford) and Stewart try), in which CP violation is believed forthcoming high statistics hyperon Raby (Ohio) reviewed other aspects to play an important role, was high experiment at Fermilab, the "classic" of discrete symmetries. Ross lighted by Kimmo Kainulainen of low-energy searches for the neutron stressed the need for discrete CERN. However this huge asymme electric dipole moment and of certain symmetries in extensions of the try is not yet understood, and to atoms, and recent high-energy Standard Model to keep everything answer this question needs a test searches at CERN's LEP electron- under control. Discrete symmetries able theory of how a Universe con positron collider of tau-pair also play an important role in the taining more baryons than production and in three-jet events attempts to understand quark and antibaryons evolved from a from b quarks. Top quarks may also lepton masses. baryosymmetric Big Bang. A candi be used to probe CP violation once Reviewing progress on theories of date for such a testable theory is the they are produced in large numbers quark masses and mixings, Raby minimal supersymmetric standard at the Tevatron and the LHC. discussed SO(10) supersymmetric model but its ability to generate the Gian Giudice of CERN reviewed CP grand unification theories, which offer required asymmetry remains to be violation in supersymmetric theories, the simplest explanation for the proven. where present bounds on CP observed Standard Model couplings. The final talks turned to a violation already give extremely Some versions even fit the observed somewhat different topic: neutrino important limits for the masses of quark and lepton masses. These masses and mixings. Jurgen Brunner supersymmetric particles. Searching ideas can be tested in the future B from CERN reviewed the status of for CP violation is thus factories, or at underground studies experiments searching for neutrino complementary to high energy such as SuperKamiokande and oscillations, where the current studies. Icarus via nucleon decays. situation is confused. Brunner looked CPT invariance, the combination of Pierre Sikivie of Florida reviewed forward to clarification from new CP symmetry with time reversal the status of the 'strong CP problem' results which could come in the next symmetry is the bedrock theorem of - why the strong interactions few years, or even months. quantum field theory, enforcing, for conserve P and CP symmetries Alexei Smirnov (Trieste) discussed instance ,equal masses for particles although the Standard Model as a possible patterns of neutrino masses and antiparticles. As discussed by whole does not. The most interesting and mixing, which may substantially John Ellis of CERN, the most solution invokes a light spin zero differ from those in the quark sector. stringent tests of CPT come from the particle, the axion. Constraints from He also reviewed the possibility of neutral kaon system in which the high energy physics searches, stellar CP-violation in neutrino oscillations - relative mass difference of the two evolution and cosmology put the substantial in the case of large particles is less than 9 x 10~19. Ellis axion mass in the range 10~3 to 10~7 mixing. Future long-baseline discussed various tests of CPT in eV. The axion would then contribute experiments could search for such CPLEAR experiment at CERN, to the dark matter of the universe and effects. possible tests using antihydrogen could be detected on Earth. The DESY workshop certainly showed that discrete symmetries and related issues remain key questions of particle physics. From Andrzej Buras (Munich Technical University) Stewart Raby (Ohio, left), Graham Ross (Oxford, centre) and Alexei Smirnov (Trieste) discuss fermion masses at the DESY Theory Workshop. 26 CERN Courier, January/February 1997 HIGH VOLTAGE POWER SUPPLIES Ultra-Compact TC Series Output 1kV-2kV 1.5W L'etancheite parfaite • Ultra-compact, PCB mountable • Low ripple • Low Noise gamme monture aluminium, colons brut, anodise argent, anodise bronze, disponible en 1 m, 3 m. Fibres.polypropylene : leurs plus gros avantages sont un garnissage et une densite continus jusqu'aux • Well-regulated, high performance extremites. Joint d'etaaicheit^ : air, poussi&re, eau, isolation dans te batiment (porte et portail). Obturation : lumiere, phonique, nettoyage, guidage, faelnage. range, aluminium fitting, natural colours, silver oxidised, Rack-Mount Package bronze oxidised, available in 1 m, 3 m. 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(41 22) 307 14 14 European Office Rosenheimerstr. 145a, Tel : +49-89-4991691 Fax : +49-89-403602 Fax (41 22)307 14 21 81671 Munchen Germany ISA Institute for V^^jl Storage Ring Facilities W University of Aarhus ^JjkW Position in Accelerator Physics (PR for ECOLE POLYTECHNIQUE ASTRID, ISA FEDERALE DE LAUSANNE The Institute for Storage Ring Facilities (ISA), which is running The Swiss Federal Institute of Technology Lausanne (EPFL) invites the dual-purpose storage ring, ASTRID, including injectors and applications for the dual position of beamlines, invites applications for a position in accelerator phys ics. ASTRID runs half time for storage of positive/negative ions PROFESSOR of and molecules and half time as a synchrotron radiation (SR) PLASMA PHYSICS source (580 MeV electrons). Concerning ion storage, the research and programs include laser cooling, electron recombination/detach- DIRECTOR OF THE CENTRE DE RECHERCHES ment, lifetime measurements and laser-ion interactions. In SR four EN PHYSIQUE DES PLASMAS (CRPP) beamlines with monochromators are operational at present, i.e. 1) a line dedicated to an imaging x-ray microscope, 2) a surface- The CRPP is a research center of the EPFL employing about 120 people physics line using a Zeiss monochromator (SX 700), 3) a surface- including PhD students. The main areas of activity are in plasma physics. The fusion related work is an integral part of the European Fusion physics line using a new SGM monochromator together with a Programme to which Switzerland participates. The main plasma physics high-resolution electron spectrometer (SCIENTA), and an un- installation at the EPFL is a 1 MA mid-size tokamak TCV (tokamak a dulator beamline with a monochromator for atomic physics. New configuration variable), which is being equipped with a 4.5 MW ECRH accelerator/storage devices are also being developed. system. As full professor, the candidate is expected to participate in teaching courses and supervising diploma work and PhD thesis work. In addition to Candidates with operational experience from electron/ion storage the managerial responsibilities of a director the candidate will lead the rings or other accelerator facilities are particularly desirable. The execution of the research programme of CRPP, including its participation in the international large programmes accessible through the European successful candidate shall take part in the operation and further Programme and participate actively at least in one of the plasma physics development of the storage ring facility, and will also be encour research activity. Interest and ability to cooperate with other laboratories is aged to take part in research programmes. ISA is funded as a na required. Industrial spin-off activities from the research programme are tional laboratory, and is located in the same buildings as the Insti strongly encouraged. The applicant must have a strong internationally tute of Physics and Astronomy, together with other centers such as recognized track record in research in the field of plasma physics, and demonstrated leadership of a research organisation. Experience in AC AP (Aarhus Center for Atomic Physics) with major activities at communicating and negotiating would be welcome. Deadline for the storage ring facility. applications: March 10, 1997. Starting date: as mutually convenient. Applicants should submit a Curriculum Vitae and a List of Publica Applications from women are particularly welcome. For further information, tions together with names of professional references not later than please contact in writing : Presidenee de l'Ecole polytechnique federate de March 1,1997, to Professor E. Uggerhoj, Director of ISA, Uni Lausanne, CE-Eeublens, CH 1015 Lausanne, Suisse versity of Aarhus, DK-8000 Aarhus C. Further information can be obtained from ISA on request, [email protected]. See also the ISA homepage, http://www.dfi.aau.dk/isa.htm. CERN Courier, January/February 1997 27 Bookshelf ascetic hermit who would occasionally These proceedings have been Particle Physics - One Hundred come in from the wilderness with a rapidly published by the UK Institute Years of Discoveries, V. V. Ezhela et compelling message, only to disap of Physics Publishing in an initial CD- al, American Institute of Physics pear again. Bohmian quantum me ROM form (the book version took a Press, ISBN 1 56396 642 5 chanics is not part of mainstream bit longer). The impressive CD physics, but for those who do cross includes an Acrobat reader to enable Several years before the official start over, like John Bell, the commitment the contents to be searched using of the 20th century, a series of can be rewarding. In the post-war 'Un- and/or criteria. To accomplish all this milestone physics experiments American Activities' purge, Bohm lost took a lot of effort (September 1995, pioneered the science which a prestigious job at Princeton and page 8), but this is clearly the way to eventually became to be known as temporarily his US citizenship, and his go. particle physics. A new book by nomadic career took him to Brazil, several authors from the COM PAS Israel and Bristol before he finally group at the Institute for High Energy settled in London's Birkbeck College. Physics, Protvino, near Moscow, and A sensitively-written book about a from the Particle Data Group effort at gifted, unusual and sometimes the Lawrence Berkeley Laboratory, provocative figure. The interaction reinforced by J.D. Jackson, has between Bohm and Oppenheimer is Books received compiled a useful summary and especially interesting, while Bohm's bibliography of more than 500 key later life was bizarre. papers marking the development of Feynman Lectures on Computation, particle physics from 1895 to the GF by Richard P. Feynman, edited by discovery of the top quark in 1995. Anthony J. G. Hey and Robin W. Some 70 percent of the listed papers Allen, Addison Wesley, ISBN 0 201 are post World War 2. The book is 48991 0. comprehensively indexed, including QCD and Collider Physics, by R.K. members of large collaborations and Ellis, J. Stirling and B. Webber, An imaginatively and carefully edited providing a useful benchmark. published by Cambridge University item of Feynman memorabilia, based However actual entries confusingly Press, ISBN 0 521 58189 3, price on courses given at Caltech from use the first listed member of the £35/$49.95 (hbk) 1983-86. collaboration, even if a Nobel Prize was subsequently awarded to Analysing experimental results in the another member of the team. light of QCD is a major responsibility in any modem particle physics The Picture Book of Quantum experiment. For experimentalists, Mechanics, by Siegmund Brandt and QCD is notoriously difficult to handle, Hans D. Dahmen, published by Infinite Potential - The Life and Times but this authoritative book by well- Springer, ISBN 0 387 94380 3 price of David Bohm, by F. David Peat, known and respected DM78 (hbk) Addison Wesley, ISBN 0 201 40635 phenomenologists traces a clear path 7, $25 through the QCD jungle and A fresh look at quantum mechanics, deserves to become a standard including some 200 computer- Throughout his life, David Bohm felt reference. generated illustrations showing the himself to be different, and this was time evolution and parameter reflected in his lifestyle and in his dependence of many different wave physics. His life was one of unfulfilled equations. searching. If one compares main EPAC 96 - Proceedings of the 5th stream physics to the church, with a European Particle Accelerator solid hierarchy of cardinals, archbish Conference, held in Sitges, near ops and bishops, Bohm was an Barcelona, 10-14 June. 28 CERN Courier, January/February 1997 People and things Bastiaan ('Bas') de Raad - 42 years at CERN hour as a Nobel Prize-winning On people proton-antiproton collider, and went on to handle beams of heavy ions. A prestigious Max Planck research With the SPS also faced with the prize goes to distinguished Russian challenge of having to inject experimentaiist Michael Danilov for electrons and positrons for LEP, research at the DESY Laboratory, de Raad conceived an ingenious Hamburg. Deputy director at scheme to safeguard the machine, Moscow's Institute of Theoretical and designed to handle protons, from Experimental Physics (ITEP), harmful electron synchrotron Michael Danilov has been a major radiation, with carefully-placed participant in DESY research since diaphragms and screens, 1978, having been a key member of supplemented by lead shielding. With the ARGUS experiment, and is one this shining armour, the SPS sailed of the initiators of the HERA-B gracefully into the LEP era. From experiment which is to be 1991-96 de Raad culminated his commissioned in 1998. Germany's CERN career as Leader of the Alexander von Humboldt foundation Technical Inspection and Safety and Max-Planck Association award Commission. the Max Planck research prize annually to six foreign and six Synchrotron, where he was one of German researchers to stimulate a John Adams' group leaders, again Lohrmann retirement flexible environment for joint research looking after beam injection and by German and foreign partners. ejection. Then came a series of key A special symposium at the German SPS roles, chairman of the running-in DESY Laboratory, Hamburg, on 25 committee, leader of the combined October, organized jointly with Bastiaan ('Bas') de Raad retires accelerator groups, and finally Hamburg University, marked the Division Leader from 1981. During formal retirement of Erich Lohrmann, this period, the SPS saw its finest who for over 30 years has pushed After a 42-year career spanning the study of elementary particles in almost all CERN's history, Bastiaan c Hamburg, decisively shaping the ( Bas') de Raad retired at the end of contours of the discipline. As well as 1996. His methodical approach and his own contributions to particle meticulous care have ensured that physics, his support of younger CERN's accelerators have overcome scientists has been much appreci challenges foreseen and unforeseen. ated. After graduating in 1956, he Arriving in 1954, he joined the proton worked on cosmic rays and elemen synchrotron magnet group, faced tary particles in Stuttgart, Bern, with the challenge of building a Frankfurt and Chicago. In 1961 he strong focusing machine, where he came to DESY, where he stimulated contributed first to magnet German-French collaboration in one measurements and then to beam of the first bubble chamber experi transfer magnets. In 1964 he joined ments at the new laboratory. He the future ISR team, where he went soon advanced to Leading Re on to become responsible for beam searcher and from 1968-74 and from transfer, injection and dumping for 1979-81 was DESY Research the world's first proton collider. Director. At CERN, he was a member Following the commissioning of the ISR in 1971, he moved to the c300 GeV project', later the Super Proton Michael Danilov - Max Planck research prize CERN Courier, January/February 1997 29 People and things Erich Lohrmann (right) at his retirement symposium at DESY with his former Stuttgart research supervisor Erwin Schopper. Protvino, near Serpukhov (Moscow Region). Under his leadership the 76 GeV accelerator, the biggest in the world at the time, was constructed and commissioned in 1967. He has also initiated and strongly promoted a wide and close collaboration with CERN, France and the USA. In 1974- 91 he was Vice-President of the Academy of Sciences of the USSR, and in 1977-92 Rector of Moscow State University. IUPAP elections At its recent General Assembly in of the Scientific Policy Committee amplitudes with the use of what were Uppsala, Sweden, the International from 1981-86 and Research Director later called "inclusive processes". His Union of Pure and Applied Physics from 1976-78. Most recently at DESY name is also related to pioneering (IUPAP) elected Jan S. Nilsson of he has been involved in the Zeus papers on finite energy sum rules Stockholm's Wallenberg Foundation experiment at HERA. In 1976 he and the "quasipotential" approach in as President of the Executive became Professor at Hamburg and quantum field theory. In recent years Council, succeeding Yoshio went on to become dean of physics. he has devoted much attention to a Yamaguchi of Tokai. Secretary He has also chaired the high energy consistent formulation of the theory General is Rene Turlay of Saclay, physics advisory committee of the of gravitation. and President Designate is Burton Federal Minister of Research, In addition to his scientific Richter of SLAC, Stanford. The new achievements, he is also one of the chairman of IUPAP's C11 key figures in the organization of high Commission on Particles and Fields A.A. Logunov's 70th birthday energy physics research in the USSR is Barry Barish of Caltech. and Russia. In 1963 he was nomi On 30 December Anatoly nated Director of the newly-created Alexeyevitch Logunov, Director of the Institute for High Energy Physics in Mikhail Vasilievich Terentyev (1935- Institute of High Energy Physics at 1996) Serpukhov, near Moscow, celebrated his 70th birthday. During his more than 40-year scientific career he has Distinguished Russian theorist made fundamental contributions to Mikhail Vasilievich Terentyev died in the early development of the Moscow on 26 September. After renormalization group methods, graduating from Moscow's Institute of to the proof and use of the dispersion Physics and Engineering in 1959, he relations and to rigorous high-energy joined the Theoretical Department of asymptotic theorems. He and his the Institute for Theoretical and collaborators adapted the power of Experimental Physics, where he the axiomatic approach to the study worked for the rest of his life. One of of analytical structure and high- the most talented students of energy behaviour of multiparticle V.B.Berestetskii, Misha Terentyev made many important contributions to particle theory. In 1963 he found a Anatoly Alexeyevitch Logunov - 70 non-renormalization theorem for a 30 CERN Courier, January/February 1997 BROOKHAVEN NATIONAL LABORATORY SCIENTIFIC STAFF POSITIONS A research center focusing on the physics program of the Relativistic Heavy Ion Collider (RHIC), hard QCD/spin physics, and relativistic heavy ion physics is expected to be established by the Institute of Physical and Chemical Research, Japan (RIKEN) at Brookhaven National Laboratory. The members of the Center will be Research Associates (two-year appointments), RIKEN-BNL Fellows (up to five- year appointments) and Visiting Scientists. Frequent workshops are planned. During the first year, beginning in fall 1997, several positions for theorists in the above categories are expected to be offered. Members of the Center will work closely with the existing high energy and nuclear physics groups at BNL. Scientists with appropriate backgrounds who are interested in applying for one of these positions should send a curriculum vitae and three letters of reference to Dr. T.D. Lee, Building 51 OA, Brookhaven National Laboratory, P.O. Box 5000, Upton, Long Island, NY 11973-5000, before March 1, 1997. BNL is an equal opportunity employer committed to work force diversity. BROOKHAVEN i) ii i NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC. Cllll on the frontier of science and technology The Department of Physics and Astronomy of the University of Basel POSTDOCTORAL POSITION seeks a EXPERIMENTAL HIGH ENERGY PHYSICS professor in experimental physics UNIVERSITY OF CALIFORNIA, SAN DIEGO working in the area of nuclear physics, in particular the in vestigation of the nucleonic and subnucleonic degrees of The Department of Physics at the University of California, San freedom of nuclei using leptonic probes. Applicants Diego invites applications from outstanding candidates for one or should be distinguished by outstanding past performance two postdoctoral researcher positions in the field of experimental in the area of nuclear physics, and have extensive ex high energy physics. These positions are subject to budgetary perience in the domain of lepton-nucleus scattering. approval. The candidate should enjoy to teach physics both at the UCSD is involved in research in Heavy Quark physics with the introductory level and in more advanced specialized CLEO detector at theCESR collider in Ithaca and the forthcoming B ABAR detector at the PEP-II asymmetric e+ e" collider at SLAC. courses. Information about this group's research interests and activities on Depending on the qualification and experience of the the CLEO and BABAR experiments can be obtained from successful applicant, the position can be filled at the http://hephpl.ucsd.edu/ associate professor level, or at the assistant professor A Ph.D. in experimental particle physics is required, with level. evidence of experience in hardware development and data analysis. In order to increase the percentage of women in research Applicants should send a copy of their curriculum vitae, including a and teaching, the University of Basel explicitly welcomes statement of physics interest, and arrange for three letters of applications of women. recommendation to be sent to: Applicants should send the usual documents with curricu Prof. Vivek Sharma lum vitae, list of publications (singling out the 5 most Physics Department, 0319 important ones), a short description of future research in University of California at San Diego terests and past activity in teaching, before v I \/ I • 9500 Gilman Drive, La Jolla, CA 92093-0319 Feb. 28, 1997 to: _\l/\l/_ email: [email protected] Dekan der Philosophisch-Naturwissen- n/|\/|\/ phone: +(619) 534 1943 schaftlichen Fakultat,Missionsstrasse 64 CH-4055 Basel,Switzerland. The nominal deadline for the receipt of the application is 20 March 1997, but the search shall continue until the position is For further information please contact U N I filled. Prof. I. Sick, [email protected] BASEL .C003411844 CERN Courier, January/February 1997 31 People and things EdnorM. Rowe 1928-96 The traditional John Adams Memorial Lecture at CERN in November this time marked 50 years of synchrotrons (September 1996, page 10). John Lawson (left), formerly of the UK Rutherford Appleton Laboratory and who was close collaborator of John Adams at the UK Harwell Laboratory, spoke on early synchrotron history in Europe, while Giorgio Brianti (right), formerly of CERN, covered the CERN machines. (Photo CERN HI 10.11.96) conscience of ITEP's Theoretical Madison he became head of the r.f. Department. He lives in the hearts of group, working on new accelerator all those who worked with him, and ideas. With the dissolution of MURA who respected and admired him. in 1967 he joined the staff of Madi son-Wisconsin, where he pushed for the establishment of the Synchrotron weak vector isovector current. (A EdnorM. Rowe 1928-96 Radiation Centre, serving as its year later an analogous theorem for Director from 1970-83. With Fred a changing strangeness vector Ednor M. Rowe, founder of Mills, he designed and built the 240 current was discovered by Ademollo Wisconsin's Synchrotron Radiation MeV Tantalus electron storage ring, and Gatto.) In 1965 (in collaboration Centre and a leading force behind its subsequently converted into a with V.S. Vanyashin) he was the first success, died last year. In the 1960s dedicated synchrotron radiation to find that vector bosons give a at the Mid-Western Universities source and the forerunner of Wiscon "wrong sign" contribution to the Research Association (MURA) in sin's big Aladdin ring. renormalization of the electromag netic charge, a phenomenon later understood as "asymptotic freedom" of non-abelian fields. For many years he was the Editor of "Yadernaya Fisika". In the last year of his life, while suffering from leukemia, he started to teach at Moscow Institute of Physics and Engineering and started to prepare a major course of lectures on elementary particle theory. M. V. Terentyev was a very generous and kindhearted man - the Virendra Singh, Director of the Tata institute for Fundamental Research, Mumbai (Bombay) inaugurated the Golden Jubilee 'Sujayata' theoretical physics symposium with a talk on the founder of the Tata Institute, Homi Bhaba (inset), and the development of theoretical physics at the Tata Institute. 32 CERN Courier, January/February 1997 Foundation for Fundamental Research on Matter Theoretical physicist The Foundation FOM advances and coordinates physics research. NIKHEF, the Dutch National Institute physicists. The succesful candidate It is being funded mainly by the for Nuclear Physics and High must have an excellent research and Netherlands organization for Energy Physics is a collaboration of publication record. He/she is ex scientific research NWO. In the Foundation for Fundamental pected to take an active part in new addition FOM receives funding from Euratom, the EU and Research on Matter (FOM), the developments in theoretical particle several commercial companies. University of Amsterdam, the Free physics, and to communicate them FOM employs about 1000 University at Amsterdam, to our research community by taking people, most of them academics, the University of Nijmegen and the part in seminars, summerschools and including PhD-students and University of Utrecht. through the supervision of students postdocs, and technicians. at the PhD-level. Good communica They work at five institutes with The NIKHEF theory group investi tion and lecturing skills are important. in FOM and about 100 working gates the theoretical aspects of sub groups at Dutch universities. atomic physics relevant for the under Assignment: FOM was founded in 1946 standing, the analysis and / or the NIKHEF offers a tenure-track and is a recognized NWO- foundation. design of present or future experi appointment, which after an initial ments. Its research programme period depending on age and experi presently covers hadron structure, ence can be extended to a contract for perturbative QCD, high-order indefinite term according to the rules perturbative calculations in the of our funding agency (FOM). standard model, supersymmetry, classical and quantum gravity and Information: string theory. The group is part of the Further information can be obtained Dutch Research School for Subatomic from the chairman of the Search Physics, and it is associated with the Committee, Dr. J.W. van Holten, Dutch National Research School in telephone +31-205925131, e-mail Theoretical Physics. [email protected] The NIKHEF theory group seeks to Application: appoint a theoretical physicist to Letters of application, including reinforce and broaden the spectrum curriculum vitae, publication list and of research in the field of theoretical the names of three references are to subatomic physics. be sent within three weeks to the personnel officer Mr. T. van Egdom, Requirements: NIKHEF, P.O. Box 41882,1009 DB We are looking for a theoretical Amsterdam, The Netherlands or to physicist with proven interest and the e-mail address: [email protected] experience in theoretical subatomic physics. Applicants are judged as to creativity, ability to establish an independent research programme Nlj^EF and to direct the research of junior CERN Courier, January/February 1997 33 The travelling exhibition 'Hadrons for Health' managed by Werner Kienzle of CERN and Alessandro Pascolini of Padua was recently on show at the Czech Academy in Prague. Left to right - Werner Kienzle, Maurice Jacob, who opened the exhibition on behalf of CERN, and Jiri Niederle, Vice Chairman of CERN Council and Director of international affairs for the Czech Academy. The linear collider route As well as CERN's LHC proton- proton collider, the other route towards the high energy frontier is via a linear electron-positron collider, the physics coverage of these two routes being seen as complementary. Over the past year, a series of meetings organized by the European Committee for Future Accelerators (ECFA) and the German DESY Laboratory, Hamburg, have group at Bristol. An ingenious experi examined the physics possibilities Cormac O Ceallaigh 1912-96 menter, he continued his studies and detector requirements for this using airborne detectors in balloons, research at collision energies of 500 Cormac O Ceallaigh (pronounced aircraft and satellites, where his GeV and more. After meetings at O'Kelly), who died on 10 October, results on heavy nuclei provided Frascati, DESY, CERN, London, and made major contributions to cosmic valuable input for our understanding Munich, a final meeting was held at ray physics. After working under of element formation in supernovae. DESY in November. The outcome Rutherford at the Cavendish will be a report submitted to the Laboratory, Cambridge, in the 1930s German Science Council next spring. and under Powell at Bristol from J.M. Valentine 1925-96 Physics aims can broadly be 1949-53, in 1953 he moved to the classified under investigating the top Dublin Institute for Advanced Former Rutherford Appleton quark, the W boson, the Standard Studies, where his experiments Laboratory Secretary J.M. ('Jim') Model and the higgs mechanism, and continued through to the era of the Valentine died on 31 October. After a supersymmetry. Space Shuttle. PhD in nuclear physics at Glasgow While this study reflects the effort and an initial career in medical going on in Europe, and in particular physics, he joined the Rutherford at DESY, where in particular linear Peter Fowler 1923-96 Laboratory in 1962 and served as collider machine research and Laboratory Secretary from 1963 until development explores the Peter Fowler, the grandson of Ernest his retirement in 1990, overseeing superconducting TESLA and the Rutherford, was, like O Ceallaigh, a the 1979 merger with the Appleton more classic S-band radiofrequency, member of Cecil Powell's cosmic ray Laboratory. work is continuing in specialist Under a recent agreement between CERN and the Spanish Centre for Industrial and Techno logical Development (CDTI), each year five young engineering graduates will come to CERN with Spanish support for two years of training in accelerator-based high technology. The first to arrive were (left to right) Guilermo Calviho Palacios, Julio Lucas Torrabla, Isabel Bejar Alonso and Montserrat Pol Fraga. (Photo Maurice Jacob) 34 CERN Courier, January/February 1997 People and things Opening the seventh 'Italy at CERN' trade Visiting CERN in November was Swedish show on 19 November, Italian Minister for Minister for Trade Bjorn von Sydow (right), Universities and Scientific and Technological seen here with CERN Director General Chris Research Luigi Berlinguer was presented with Llewellyn Smith. a copy of 'Nel Mistero dell Universo', the Italian (Photo CERN HI 7.11.96) edition (De Agostini, Novara) of 'Search for Infinity', the book on CERN science by Gordon Eraser, Egil Lillestol and Inge Sellevag. (Photo CERN HI 25.11.96) : Bldg 51 OA, BNL, Upton NY 11973, Italy, from 10-12 September, the week Meetings Telephone: 516-344-3903, email preceding the International Confer- Chrien ©bnl.gov fax: 516-344-5568 ence on Medical Physics in Nice. The next High Energy Physics Information from Roberto Cirio, International Euroconference on The International Symposium on /A/FA/ TO, Via Giuria 1,1-10125 Quantum Chromodynamics "Strangeness in Quark Matter" will be Torino, fax +39 11 6699579, Gerhard (QCD97), marking the 25th held from 14-18 April in Santorini, Kraft, Biophysics GSI, Planck Str. 1, anniversary of QCD, will be held from Greece. Contact D-64291 Darmstadt, fax +49 6159 3-9 July in Montpellier (France). [email protected] or 712106, or Enzo Sacco, IEO sez. Deadline for registration, abstracts [email protected] TERA Ml, via Ripamonti 435, 20141 and papers is 9 May. Contact: QCD Milano, fax +39 2 57489208 secretariat or S. Narison, Laboratoire The 6th Workshop on Heavy Charged de Physique Mathematique et Particles in Biology and Medicine will The Proceedings of the 1996 Zuoz Theorique, UM2, Place Eugene be held at Baveno, Lago Maggiore, Summer School on Physics with Bataillon, 34095 Montpellier Cedex 05 (France). Phone: (33) 04 67 14 35 68 Fax: (33) 04 67 54 48 50, e-mail: qcd @ Ipm. univ-montp2. fr The International Conference on Hypernuclear and Strange Particle Physics - HYP97 - will take place from 13-18 October at Brookhaven National Laboratory, Upton NY 11973, USA. Contact R. E. Chrien, Heavy ion transition. Old and new spokesmen for the NA49 experiment at CERN - Reinhard Stock (right) of Frankfurt hands over to Peter Seyboth of Munich's Max Planck Institute. CERN Courier, January/February 1997 35 People and things New Division Leaders at CERN: left to right - Jurgen May (Information Technology), Romeo Perin (Supplies, Procurement and Logistics) and Helmut Schdnbacher (Technical Inspection and Safety Commission) Neutrinos is available from Christine Kunz, Paul Scherrer Institute, Wurenlingen and Villigen, 5232 Villigen PSI, Switzerland. Tel +41 56 310 42 23, fax: +41 56 310 32 94, e- mail Christine. [email protected] Last summer, CERN translator Frangois Siohan (who handles the lion's share of the translation for the French edition of the CERN Courier) Beyond the LHC bravely set out to break the world cycling record for vertical height in 24 hours. Using the 11.2 kilometre stretch between Gex at the foot of the Very Large Hadron Collider Physics Jura mountains near CERN and the Faucille and Detector Workshop Physics At (sickle) pass, the indomitable Frangois, 55, relentlessly scaled the 711 metre ascent 21 The High Energy Frontier Beyond the times, making a total climb of 14,931 metres. LHC is the title of a workshop The previous record was 13,552 metres. sponsored by Fermilab and the US Department of Energy to be held March 13-15 at Fermilab. It will concentrate on the physics and detector issues associated with a hadron collider with a collision energy of the order of 100 to 200 TeV. Further information from Diane Sellinger, Physics Section, Fermi National Accelerator Laboratory, MS #122, P.O. Box 500, Batavia, Illinois 60510, Phone: 630 840-3201, E-mail: [email protected]. 36 CERN Courier, January/February 1997 RESEARCH ASSOCIATE LIP - LAB ORATORIO DE INSTRUMENTACAO E PARTICULAS SUPERCONDUCTING RF TECHNOLOGY LISBON CORNELL PROJECT ASSOCIATE UNIVERSITY LABORATORY OF NUCLEAR STUDIES ELECTRONICS FOR PARTICLE PHYSICS We anticipate an opening for a Research Associate to work on the development, installation, and operation of the Superconducting RF systems for the Cornell electron- The LIP-Lisbon institute invites applications for a positron colliding beam facility, CESR. Over the next few project associate position, available immediately, to years, the major activities for the Laboratory will be the participate in the development of the CMS operation and upgrade of CESR with the goal of substan calorimeter trigger system. The position offers tially improving the luminosity. R&D is in progress on opportunities for the development of trigger circuits major components such as superconducting cavities, high prototypes to be evaluated in test beam. The person power input couplers, high power windows, higher order will be based at CERN. mode loads, cryostat, refrigeration, RF power distribution, instrumentation, and controls. Candidates should have an electronics engineer This is a three-year appointment with the expectation degree and experience with electronics for trigger of renewal, subject to mutual satisfaction and the availabil and data acquisition systems in high energy physics. ity of funds under our NSF contract. A Ph.D. in physics or Knowledge of modern electronics design methods engineering is required with related experience in some of and tools is necessary. Experience with control and the areas outlined above. Please send an application with data acquisition buses is also required. curriculum vitae and arrange for at least two letters of references to be sent to: Letters of application, including a statement of Dr. Hasan Padamsee experience and interests, supported by a curriculum Cornell University vitae and the names and addresses of two referees, Newman Laboratory should be sent to Dr. J. Varela, CERN, CH-1211 Ithaca, NY 14853-5001 Geneva 23, Switzerland. E-mail to: [email protected] Cornell University is an equal-opportunity, affirmative-action employer. DESY announces several MIT DESY "DESY-Fellowships" Postdoctoral Associate for young scientists in experimental particle physics to The Bates Linear Accelerator Center invites participate in the research mainly with the HERA collider applications for a postdoctoral position in the Polarized Injector experiments H1 and ZEUS or with the fixed target expe Group. The successful candidate will join the group's activities in riments HERA-B and HERMES. New fellows are selected further improving and characterizing the delivery of high quality twice a year in April and October. polarized beam for the parity violation SAMPLE experiment which requires high quality polarized beam of unprecedented DESY fellowships in experimental particel physics are stability. Will also participate in the beam delivery to other approved physics experiments and contribute to the upgrade of awarded for a duration of two years with the possibility the polarized source and the laser system to meet the high peak for prolongation by one additional year. current requirements of the South Hall Ring (SHR). The salary for the fellowship is determined according to Requirements: a Ph.D. in experimental or applied physics with experience in and knowledge of accelerator based photo- tarifs applicable for public service work (I la MTV Ang.). emission. Must be able to efficiently function as a team member with demonstrated attention to technical details in systems with Interested persons, who have recently completed their similar complexity. Working experience with delicate UHV Ph.D. and who should be younger than 32 years are in systems also required. Experience with charged particle beam vited to send their application including a resume and the optics and working knowledge of high power laser systems and electro-optical devices and the operation of facilities dedicated to usual documents (curriculum vitae, list of publications, beam delivery desirable. The position may require rotating shift copies of university degrees) until 31 of march 1997 work during beam operation of the source. Bates is located in to DESY, Personalabteilung - V2 NotkestraBe 85, Middleton, Massachusetts. D-22607 Hamburg. They should also arrange for three Please send a cover letter, a current C. V., and the names of letters of reference to be sent until the same date to the three references to: Mr. Richard Adams, Laboratory for address given above. Nuclear Science, MIT, Bldg. 26-516, 77 Massachusetts Avenue, Cambridge, MA 02139. MIT encourages applications from women and minorities. Handicapped applicants with equal qualifications will be prefered. Massachusetts Institute of Technology DESY encourages especially women to apply An Equal Opportunity/Affirmative Action Employer As DESY has laboratories at two sites in Hamburg and Non-Smoking Environment in Zeuthen near Berlin, applicants may indicate at which location they would prefer to work. CERN Courier, January/February 1997 37 People and things Claudio Villi 1922-1996 CERN Council External The December meeting of CERN's correspondents governing body, Council (see page 1) was the last to be presided over by Hubert Curien of France. Luciano Argonne National Laboratory, (USA) D. Ayres Maiani of Italy now takes over. At the Brookhaven, National Laboratory, (USA) December meeting, Fernando P. Yamin Barriero of Spain was appointed to CEBAF Laboratory, (USA) the Scientific Policy Committee. S. Corneliussen Alberto Scaramelli is appointed Cornell University, (USA) leader of CERN's Technical Support D. G. Cassel Division from 1 July, succeeding Fritz DESY Laboratory, (Germany) Ferger, and Alvaro de Rujula is P. Waloschek appointed leader of CERN's Theory Fermi National Accelerator Laboratory, Division from 1 July, succeeding (USA) Judy Jackson Gabriele Veneziano. GSI Darmstadt, (Germany) G. Siegert INFN, (Italy) DOE Office of High Energy and A. Pascolini Nuclear Physics IHEP, Beijing, (China) including a model for the internal Qi Nading In the US Department of Energy structure of the nucleon, which was JINR Dubna, (Russia) (DOE), S. Peter Rosen has been probed in the historic Stanford B. Starchenko appointed Associate Director for High experiments by Robert Hofstadter. KEK National Laboratory, (Japan) In 1960 Villi became professor of S. Iwata Energy and Nuclear Physics (HENP), taking over from Director of the High theoretical physics at Parma and in Lawrence Berkeley Laboratory, (USA) Energy Office John O'Fallon who has 1962 moved to Padua to teach B. Feinberg been serving as Acting Associate nuclear physics and then Los Alamos National Laboratory, (USA) mathematical methods till his C. Hoffmann Director for High Energy and Nuclear NIKHEF Laboratory, (Netherlands) Physics following the retirement of retirement. Margriet van der Heijden Wilmot Hess. He pushed the development of Novosibirsk Institute, (Russia) nuclear physics in Italy, promoting in S. Eidelman particular the upgrade of the Legnaro Orsay Laboratory, (France) Claudio Villi 1922-1996 National Laboratory and the creation Anne-Marie Lutz of the National Southern Laboratory PSI Laboratory, (Switzerland) Claudio Villi, theoretical physicist and at Catania. He served as INFN P.-R. Kettle former President of the Italian Istituto President from 1970 - 75 and Rutherford Appleton Laboratory, (UK) succeeded in strengthening the Jacky Hutchinson Nazionale di Fisica Nucleare (INFN), died on 18 December. Born in structure of INFN and its role as a Saclay Laboratory, (France) Elisabeth Locci Trieste, he took part in the Italian State institution, in creating a network liberation with the British army, of relations with Italian universities IHEP, Serpukhov, (Russia) Yu. Ryabov subsequently graduating in physics and other research bodies, and in Stanford Linear Accelerator Center, (USA) at Trieste and starting nuclear promoting international cooperation. M. Riordan physics research with the Padua In 1976 he was elected Senator of TRIUMF Laboratory, (Canada) theoretical group. His main the Italian Republic, paying particular M. K. Craddock contributions were in the area of attention to science, energy and nuclear structure and reactions, environmental problems. A man of 38 CERN Courier, January/February 1997 People and things broad scientific, cultural and social Daresbury Laboratory, a member of Meeting interests, he gained prestigious CERN's Research Board and Chair awards for his scientific activity, his man of the SPS Experiments Com The 5th Topical Seminar on "The devotion to the development of mittee. He has recently served on a Irresistible Rise of the Standard science and for the promotion of review committee for Dutch physics. Model" will take place in San Miniato international cooperation. Peter Higgs of Edinburgh receives al Todesco, Italy, from 21-25 April at the prestigious Paul Dirac Prize for the Centro Studi 7 Cappuccini". The his contributions to gauge invariant Seminar is organized by F.-L. UK Institute of Physics Awards field theories and to the spontaneous Navarria/Bologna and P.G. Pelfer/ symmetry breaking mechanism Firenze, and is sponsored by IN FN, The 1997 list of awards by the UK which customarily bears his name. Universita di Bologna, Universita di Institute of Physics includes four Roger Forty of CERN receives the Firenze, Regione Toscana. people well-known at CERN, either Charles Vernon Boys Prize, reserved Attendance, by invitation only, will be directly or through their work. for young researchers, for his work limited to approximately Alexander Donnachie of on B-particle physics with the Aleph one hundred. Information: F.-L. Manchester receives the prestigious experiment at CERN's LEP electron- Navarria, Dipartimento di Fisica, V.le Glazebrook Prize. As well making positron collider. Berti-Pichat 6/2, 1-40127 Bologna, tel many contributions to Timothy Berners-Lee of MIT +39 51 6305082/6305101, fax+39 phenomenology, he has also been receives the Duddell Prize for his 51 247244, e-mail [email protected] Head of the High Energy Particle invention of the World Wide Web at http://www. bo. infn. it/conferences/ Physics Division at the UK's CERN in 1989. sminiato-new/sminiato97.html Air Bearings Precision Rotary Table Standard diameters are 60, 90, 120, 200, 300, 400 and 600 mm. Centering and levelling of the rotary tables can be accomplished either manually or automatically. The drive and positioning are designed to suit specific customer requirements. Positioning accuracy of < 1 arc. second. The radial and axial runout is 0,08|im, depending on diameters and requirements. Increasing demands in the field of precision and gauging machine technology require the utilization of air bearing guidance systems. KUGLER air bearings have been developed with respect to state-of- the-art technology and many years tradition of mechanical excellence. KUGLER Tel.: 0049(0)7553-92 00 0 Fax: 0049(0)7553-92 00 45 Heiligenberger StraBe 100 88682 Salem - Germany Laser Optics & Systems - Interferometers - Air Bearings - Micro-machining Systems CERN Courier, January/February 1997 39 UNIVERSITY OF FLORIDA EXPERIMENTAL HIGH ENERGY PHYSICS ASSISTANT PROFESSOR The University of Florida invites applications for a tenure track Assistant RESEARCH Professor position in experimental high energy physics to begin August 1997. Requirements include a Ph.D., demonstrated accomplishments in GROUP LEADER this field of research and good teaching ability. Advanced Photon Source The new faculty member would become part of a strong and rapidly expanding research group that presently includes five high energy experi Argonne National Laboratory, located 20 miles ment faculty and seven high energy theory faculty. The experimental group southwest of Chicago, is one of the premier scien will continue to expand in the future in the area of hadron collider physics. Currently the Florida group is leading in the design and construction of the tific research and development organizations in Endcap Muon System of the CMS experiment at CERN. We also partici the United States. An opportunity to lead the pate in the CLEO experiment at Cornell and the CDF and MINOS experi Laboratory's Accelerator Physics Group now ex ments at Fermilab. One of the major muon detector development/testing ists for a physicist who has achieved a position of sites for CMS is expected to be located in Florida. The new faculty mem ber is expected to play a leading role in hadron collider experiments (CMS stature in the field of accelerator physics, and is and CDF). Our work in these activities is enhanced by a powerful simula specifically acknowledged for research and lead tion and data analysis computer system, and the construction of a new build ership in the area of synchrotron light sources. ing for the physics department which will have large and well equipped laboratory space for hardware development and will be completed late 1997. We would look to the selected candidate to develop Applicants should send curriculum vitae, bibliography and a description and maintain an excellent accelerator research pro of research and teaching interests to HEE Search Chair, Department of gram, by expanding the capabilities of the Ad Physics, P.O. Box 118440, Gainesville, FL 32611. Please arrange to have vanced Photon Source accelerator systems and your reference letters sent or provide the names of at least three references for the Committee to contact. Applicants with questions may contact the developing innovative accelerator physics con Search Chair, Professor Guenakh Mitselmakher, by mail or by email at cepts into new research opportunities. Responsi [email protected] or by telephone at 352/392-5703. The office bilities include providing technical leadership and fax number is 352/392-8863. The deadline for receipt of applications is management supervision to the Group, organizing February 28,1997. seminars and a visiting scientist program and un The University of Florida is an equal employment opportunity/affirmative dertaking occasional teaching responsibilities sat action employer. Anyone requiring special accommodations to complete applications should contact the Search Committee Chair. the University of Chicago. Qualified candidates will possess a level of knowl edge typically achieved with 10+ years' experi ence in accelerator physics research as well as an established reputation in the accelerator commu Research Associate Position nity at large. Experience in supervising the re University of Virginia search of Ph.D. candidates and postdoctoral re Experimental High Energy Physics searchers, and directing a research group is The University of Virginia Experimental High necessary. Ph.D. or equivalent credentials are a Energy Physics group is seeking qualified applicants requisite. for a Research Associate position to work on the physics of CP violation. On the short term, this Argonne offer a stimulating professional environ work will focus on the KTEV experiment at Fermi ment, competitive salary and excellent benefits National Accelerator Laboratory, and on a longer package. For consideration, please send your re time scale, on the LHC-B beauty physics experiment sume and the names and addresses of three refer at CERN. This position is now open. The successful ences to: Argonne National Laboratory, Attn: candidate is expected to play an important role in Walter D. McFall, Box APS-117811-60, Employ the KTEV experiment in the operation of an e+e- ment and Placement, 9700 South Cass Avenue, trigger based on a transition radiation detector and in the development of lepton detectors and triggers Argonne, IL 60439. Telecommunications Device for the LHC-B experiment. Applications including for the Deaf630/252-7722. Resumes are electroni curriculum vitae, a list of publications, and three cally scanned and processed. A letter quality re letters of reference should be sent to: sume with a standard typeface is required (no underlines or bold, please). An Prof. B. Cox Equal Opportunity/Affirma Physics Department, McCormick Rd. University of Virginia tive Action Employer. Charlottesville, VA 22901 O C5 For additional information, Information concerning this position may be please refer to Argonne's O obtained through e-mail at: Home Page on the Internet — s http://www.anl.gov/welcome.html. /ry 0$ Cox @ UVAHEP.phys.virginia.edu The University of Virginia is an equal opportunity employer. CERN Courier, January/February 1997 X-RAY DETECTOR XR-100T FEATURES 200 eV RESOLUTION Si-PIN Photodiode Technology Breakthrough Peltier Cooler Cooled FET All Solid State Design / No More Liquid Nitrogen !! 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