Particle Physics in Budapest

Particle Physics in Budapest the threshold for charmed D meson pair production and below the thres hold for production of its excited state D*. This peculiar kinematical confi guration has made it possible to ex At the Conference on Particle Phy tract highly accurate and important sics held at Budapest, July 4-9, an information on the D meson from the unusually large amount of new and decay of this new (3772) state. exciting experimental results was pre Second, from the DORIS e+e- col sented. liding beam machine came first evi Certainly an outstanding highlight dence for the strange member of the was the discovery of a very heavy charmed pseudoscalar meson family : dimuon resonance with mass around the F meson. All these results round 9.5 GeV in the process p+ nucleus→ off beautifully our picture of the rôle µ + µ - + anything. The experiment of the fourth quark (flavour) : charm. had been performed at the Fermi A large amount of new (indirect) National Accelerator Laboratory with evidence for the heavy lepton τ has 400 GeV protons by a Columbia- accumulated from the DORIS and FNAL-Stony Brook collaboration. This SPEAR e+e- machines. The new re new state at 9.5 GeV probably indi sults are in nice agreement with the cates the existence of at least a fifth theoretical expectations for such a quark (flavour), just as the previously heavy lepton. discovered J/ψ resonances announ A series of three fairly narrow peaks ced the existence of the fourth quark (at 1498, 1820 and 2130 MeV) has (flavour) : charm. Due to the limited been reported from the e+e" colliding resolution of the experiment, it is yet beam facility ADONE. The masses an open question whether this enhan are consistent with expectations for cement around 9.5 GeV is a single higher spin one 0 meson excitations. (broad) resonance or — as predicted However, the reported widths seem theoretically — consists of several somewhat too narrow, so perhaps narrow positronium-like bound states there is interesting new physics about of the new quarks. to emerge. Far-reaching new results came Even in the domain of “old” phy from charged current deep inelastic sics (i.e., neither involding charm nor v and v interactions. These experi quarks beyond charm) there was in ments have been performed at the teresting and intriguing news : two new CERN-SPS accelerator and at groups working at the CERN Omega FNAL. A previous experiment (Har- spectrometer have reported the disco vard-Penn-Wisconsin-FNAL collabora very of new heavy baryon-antibaryon tion) had claimed to see an ano resonances at 2020 MeV, 2200 MeV malous change in certain v distribu and 2950 MeV with surprisingly tions for v energies beyond 30 GeV. narrow widths. They are candidates This anomaly has a strong conse for the predicted “baryonium” states. quence : it had to be interpreted as Theoretically one expects a somewhat a manifestation of right-handed cur longer lifetime for “baryonium” than rents coupling to new quarks beyond for normal mesonic resonances due charm of mass around 5 GeV. In par to the topological peculiarity of baticular the new high statistics v and v ryons as composites of three quarks. experiment from CERN (CERN-Heidel- The puzzle with the new states is berg-Dortmund-Saclay collaboration) that their widths are considerably has clearly demonstrated now that smaller than may be expected in such such an v anomaly does not exist. schemes. Moreover all v and v results are in In the domain of “theoretical nice agreement with the naïve spin theory” much effort was devoted to 1/2 quark-parton model (possibly ador a better understanding of quark dy ned with some “asymptotic freedom” namics in general and the quark corrections). This CERN experiment confinement problem in particular. and the other experiments performed Interesting new developments in the at the big CERN bubble chamber field of “supergravity” and in the BEBC and at FNAL agree with each investigation of non-perturbative so other. lutions of classical and quantum field Important progress came again theories were reported. from e+e- physics : first, a new ψ A special highlight was certainly resonance with a mass of 3772 MeV the beautiful and inspiring lecture by has been discovered at the SPEAR Prof. Dirac celebrating the 50th anni e+e- colliding beam machine. This versary of the Dirac equation at this state is a particularly interesting Budapest Conference. member of the J/ψ family (“charmonium”) since it is located just above F. Schrempp W ILE Y LONDON NEW YORK SYDNEY TORONTO THE UNCERTAINTY PRINCIPLE AND FOUNDATIONS OF QUANTUM MECHANICS edited by W.C. Price and S.S. Chissick, both of King's College, London. This commemorates the formulation of quantum (or matrix) mechanics by Heisenberg, and collects topics into four main groups dealing respectively with Uncertainty Relations, their history and philosophical implications, particularly on causality, Measurement Theory, Formal Quantum Theory and Applied Quantum Mechanics. April 1977 590 pages £19.50/$38.00 0471 99414 6 VIBRATIONAL STATES by S. Califano, University of Florence. Fulfils aneed for ageneral theoretical introduction to vibrational spectroscopy at a graduate level, but includes topics of amore advanced character for the benefit of research workers. 348 pages 0471 12996 8 April 1976 £16.75/$32.10 OPTICS OF THIN FILMS by Z. Knittl, Palacky University, Czechoslovakia. Describes the basic theory of dielectric, metallic and inhomogeneous (dielectric) layers. The matrix treatment is the general method of approach, but other existing methods, including the graphical ones, are also followed. (Wiley Series in Pureand Applied Optics). February 1976 548 pages £15.00/$30.70 0471 49531 X INTRODUCTORY EIGENPHYSICS: An Approach to the Theory of Fields by C.A. Croxton, Cambridge. November 1974 286 pages £8.65/$17.30 (cloth) 0471 189294 November 1974 286 pages £4.95/59.90 (paper) 0471 189308 INTRODUCTION TO LIQUID STATE PHYSICS by C.A. Croxton, Cambridge. April 1975 296 pages £9.50/$19.00 0471 189332 April 1975 296 pages 0471 189340 £4.95/59.90 NUCLEAR ELECTRONICS by P.W. Nicholson, University of London. April 1974 402 pages £10.90/$21.80 0471 63697 5  (...truncated)