Uppsala Spells Hope

Uppsala spells hope Abdus Salam (front row, right) leads the notetakers at a plenary session of the recent EPS International High Energy Physics Conference, held in Uppsala, Sweden. In the last few years, the particle physics community has experi enced something of a backlash. Indications of effects beyond its Standard Model - the electroweak synthesis plus the quantum chro- modynamics (QCD) picture of quark interactions - have disappeared on closer scrutiny, while the ex pected sixth ('top') quark is still missing. In addition, the proton does not appear to decay, at least not within 1032 years, ruling out the simplest 'grand unified' models encompassing both the electroweak and the quark interaction sectors. However at the European Physi cal Society's International High Energy Physics Conference in Upp sala, Sweden, from 25 June to 1 July, the message was one of hope. There are excellent pros pects of unravelling good physics the monopoly of the UA1 and UA2 reviewed the present status of this with the impressive range of accel experiments at the CERN proton- research. It is not yet clear whether erators and storage rings planned antiproton collider for W and Z these materials will be suitable for or under construction. This tran physics with the first W and Z making superconducting magnets. sition to a new energy range was candidate events from the CDF Dave Jackson, reviewing the status reflected in the plenary talks, in detector at the Fermilab Tevatron. of the US SSC Superconducting cluding many status reports on Although presented as candidates, Supercollider project, did not con new projects. plenary speaker Pierre Darriulat of sider them significant at the pre The 600 physicists who came CERN and the UA2 experiment sent stage of the SSC design. to Sweden's oldest university, was convinced enough to invite In his talk on particle physics founded 510 years ago, heard the the CDF team to join the W/Z club. and cosmology, John Ellis of CERN first results from the new Japanese With CERN's new ACOL Anti- presented the emerging view on TRISTAN electron-positron collider. proton Collector coming into oper the supernova physics. He also With the machine running at 25 ation to boost the antiproton sup stressed the importance of the GeV per beam, the VENUS, AMY ply, exciting competition is fore 'dark matter' problem - gravita and TOPAZ experiments compare seen between Europe and the US. tional indications that much of the the production levels of hadrons In his summary, Guido Altarelli material of the universe is electro- and of muons. Their results so far pointed out that two of the big magnetically invisible. Many pro are compatible with what was seen physics discoveries of the past posed solutions imply the exist at slightly lower energies in the year were in other fields but never ence of new particles, and inge PETRA ring at the German DESY theless have important implications nious new detectors are being Laboratory several years ago and for high energy physics - the dis designed. as yet show no signs of the top covery of the new high tempera Terence Sloan reviewed quark quark. ture superconductors and the ob interactions deep inside hadrons, Key ingredients in the Standard servation of the 1987 supernova. and the measured structure func Model are of course the W and Z One of the pioneers of the new tions describing the quark content bosons carrying the weak nuclear boom in ceramic superconductors of nucléons and other particles. force. Uppsala marked the end of - Georg Bednorz of IBM Zurich - Recent results from the European CERN Courier, September 1987 1 @ B&S INTERNATIONAL FRANCE ]• The « Turnkey-package » A team : Employing real profesionals in electronic 11^ design and printed circuits, our team has a thorough knowledge in this field. electronic diagrams and printed circuits A service : • A collaboration for many years with the CERN. • Our offices are located within one kilo meter of both of the CERN laboratories. • Fitted with high-performance tracers and laser printers, we work in all gra phic areas : wiring diagrams, reports B&S INTERNATIONAL FRANCE, with diagrams, plots, etc... means.110 specialists working in electro nics, electromechanics and mecanics etc., at the CERN site. 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B&S INTERNATIONAL FRANCE S.A.R.L « LA DIAMANTERIE » | 46, RUE DE GENÈVE S c _ mean CT r^cMic_Dni m i v TÉI • rc\ ao nn OR FAY • ao 9« ar TI Y • F_q«^nAA m mo IMTPRMP HPRM • 7nnfi m m Muon Collaboration.on spin- positron excitations do not support dependent structure functions the intriguing signal seen at the From Uppsala show that an expected condition Darmstadt GSI Laboratory, how (Ellis-Jaffe sum rule) does not ever a low energy positron scat to Hamburg work. tering experiment in Stockholm Many of the results presented The 'superstring revolution' does show an unusual peak in the at the European Physical So which has activated many theore same region as the GSI effect, ciety's International High En tical physicists and mathematicians supporting also an Oak Ridge ergy Physics Conference in in recent years has now entered study. Uppsala, Sweden, in June a consolidation phase. Although There was considerable theore were underlined or further the hope for a unique theory has tical discussion on the 'new phys elaborated at the International more or less evaporated, super- ics' potential of the new machines. Symposium on Lepton-Pho- string advocate Michael Green was In the session covering jet phys ton Interactions at High Ener still optimistic as the enormous ics, Henry Suter of CERN presented gy in Hamburg a month later. technical effort worldwide is being recent results from the NA10 ex A report of the Hamburg rewarded by a deeper under periment at CERN on the produc meeting will feature in our standing of the subtle mathematical tion of muon pairs by different October issue. issues involved. beams of hadrons (see July/Au Even if contact with experiment gust issue, page 17), where the is difficult, the mere possibility of angular distribution has an unex of the various models are gradually incorporating quantum gravity and pected variation with transverse converging. the Standard Model into a common momentum. Preliminary results on Measurements from the CERN framework is itself a triumph for hadron jets from the CDF experi Collider on the detailed behaviour string theory. ment at the Fermilab Tevatron of forward elastic scattering show In another theoretical plenary were presented by A. Garfinkel of that the ratio of the real to the talk, Ludvig Faddeev of Leningrad Purdue. The produced jets extend imaginary parts of the amplitude reported on attempts to quantize out to 150 GeV transverse mom is higher than expected from extra theories containing mathematical entum. polation from lower energies. If anomalies. Although the physical Another embarrassment for the this proves correct, it means a properties of such systems remain Standard Model - production of rapid increase in reaction rates to be determined, Faddeev empha pairs of like sign muons in neutrino above 1 TeV. sized that anomalies are not as interactions - is evaporating, with The session on lepton properties disastrous as was once thought. results from the CCFR group at included an interesting talk by The tradition of the EPS High Fermilab (see also June issue, page M. Roos (Helsinki) who discussed Energy Physics Conferences is for 18). the ways of extracting information intense parallel sessions during A large part of the session on on the neutrino mass from this the first days, providing a mass 'soft' hadronic interactions was year's supernova information. An of information and Uppsala was devoted to a comparison of the upper limit of around 20 eV or no exception. multiparticle production seen in even less can be extracted, and In the session of physics beyond fixed target experiments and at there are arguments which pull the the Standard Model, the UA1 and the CERN Collider. Effects such as limit down even further. However UA2 collaborations presented new the (KNO) scaling violation or the Roos emphasized that given our and updated bounds on particles development of strong forward- limited understanding of what hap- as yet unseen but implied by the backward correlations were con penned in the supernova, these oretical ideas such as supersym- firmed, and with improved accu results should be used with care metry and quark compositeness. racy. and laboratory experiments are as According to UA1, the top New developments of 'fragmen useful as ever. quark now has to be heavier than tation' models describing the for Alvaro de Rûjula of CERN also 44 GeV. mation of hadrons from quarks discussed the neutrino implications Limits from 'beam dump' exper were presented and discussed, of the supernova, and speculated iments on light short-lived electron- and it seemed as if the predictions on the possibility that it banged CERN Courier, September 1987 3 experiments also took data with protons, an effort is being made to sort out collective effects. With new precision data on deep inelastic scattering probing the Beauty without charm deep interior of the struck nu cléons, the ratio of the longitudinal to transverse production rates New physics result announced Together with recent results measured at Stanford in certain at the International Symposium from the same experiment on kinematic regions (momentum on Lepton and Photon Inter the 'mixing' of electrically neutral transfer less than 10 GeV2) is larg actions at High Energy held in B mesons, this information helps er than the theoretical predictions.

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