[en] The program of the seventh meeting followed the traditional pattern of selecting invited papers on new physics results obtained at new machines such as the TRISTAN e⁺e^-, and the Tevatron antipp colliders. Review papers were also presented covering new and detailed results from the CERN antipp collider, and the e⁺e^- colliders at Cornell, DESY and SLAC. New results on such interesting topics as CP-violation, heavy flavour production and heavy-ion interactions, obtained by fixed target experiments, were also reviewed. Our theoretical colleagues made excellent reviews covering new important developments in the field, from the Standard Model through the Superstring phenomenology. As usual, the conference reserved a session for the prospects for physics at future accelerators

[en] For the long range future of CERN, the long range planning commission has explored various options, taking into account the actual development of physics and existing facilities. The solutions envisaged are Large Hadron Collider and e⁺e^- collider (CLIC) in the 1-10 TEV range

[en] The LEP project has always been understood as an e⁺e^- collider with an energy of 100 GeV per beam. In 1981 it was decided to introduce a step in energy and to make available as soon as possible 50 GeV per beam, the so called LEP I phase. A tremendous effort is underway to construct both the machine and the detectors, most of this concentrated on the start of physics with LEP I. Nevertheless a workshop was proposed to study the experimental and theoretical aspects of the physics feasible at LEP 200. It was organized by ECFA under the chairmanship of W. Hoogland and held at Aachen in September 29^th 1986. Many contributions were presented and the summary was given by Professor D. Perkins. A few weeks ago the proceedings appeared. I have used essentially all the various results of the working groups of the workshop and I will refer to the proceedings as the Green Book. Many discussions and results were already mentionned in Physics at LEP referred to as the Yellow Book. An excellent lecture given by R.P. PECCEI at the CERN School has also been very useful to me. In this report I would like to discuss the following points: upgrading of the machine to 200 GeV. Physics to the W's. Higgs boson search. Toponium physics. Non-standard physics, and finally give a conclusion

[en] This review covers the current experimental situation of CP violation but is therefore restricted to a discussion of the Kaon neutral system. The Kaon neutral decays in which CP has been tested are the following: 1) In the decay K_L →π⁺π^-π⁰ an asymmetry in the energy distribution of the two charged pions would be due to CP violation. 2) In the decays K_L→π^±e^-+v and K_L→π^±μ^-+v, a charge asymmetry is observed in the rates with positive and negative leptons respectively. 3) Limits on the deacays of K_S into three pions are expressed by the ratio of decay amplitudes. 4) The decays K_L→π⁺π^- and K_L→2π⁰ have both been measured accurately, with a ratio of decay amplitudes defined. Based on the published material, we may summarize the experimental status of CP violation in the Kaon neutral system as follows: - CP violation has been observed definitively in the Kaon neutral system; - CP violation has not been observed anywhere else; -all experiments are consistent with the Superweak Model. It is interesting to note that the phenomena of CP violation are experimentally compatible with CPT conservation, and that T violation in the decay Kaon neutral →2π is therefore a necessary consequence. The observation of CP violation has found a natural explanation in the framework of the Kobayashi-Maskawa model

[en] I will especially emphasize new developments concerning the rare decays of K-mesons which might throw light on the relations between leptons of different flavor. For the most part, the interesting rare decays of the K-mesons are presumed to be mediated by massive particles in such a manner that the transition rate characteristic of the decay varies inversely as the fourth power of the mass of the mediating particle. Assuming that all fundamental couplings are the same (excepting factors of the order of one) one can estimate the range of mass covered by the searches by comparing the transition rates under inquiry with known transition rates mediated by known particles (especially the W and Z) of known mass. Such comparisons suggest that our searches for rare K-decays can be expected to probe mass scales of the order of 100 TeV. Eventually, the broad range of searches now underway should tell us much about this heretofore unexplored mass region. Is this region but a trackless desert. Or are their arcane and exotic particles to be found which reflect dimly on our low energy world

[en] A summary of the UA1 results of the last years is presented. The properties of the Intermediate Vector Bosons together with the derived standard model parameters are discussed. The transverse momentum distributions of the fundamental gauge bosons are compared with each other. We observe two outstanding events with large transverse momentum W's and two jets, forming the W mass. Beauty production and Beauty oscillations are discussed and the search for top is described in detail. From the W and Z cross-sections times branching ratios the number of light neutrinos was derived. The standard model is in a better shape than it ever was. We failed to observe new particles

[en] Recent results from the UA2 experiment at the CERN p anti p collider are presented. The full statistics is used to measure the properties of the Intermediate Vector Bosons and to test the Standard Model. Searches for exotic processes are also described

[en] In the present talk, I shall concentrate on the problem of the quadratically divergent Higgs masses (with supersymmetry as a potential cure) and the problem of the non-renormalizability of gravity with a possible solution given by superstring theory. In all these examples we see a quest for renormalizability and finiteness; a better theory is a theory with less divergences. Given this basic assumption, let us now discuss the standard model in more detail. Certainly, this model is not the final model of the world since it contains too many free parameters (masses, mixing angles, coupling constants). Also the more fundamental questions about the origin of the gauge group SU(3)xSU(2)xU(1) and the reason for the existence of three families of quarks and leptons cannot be answered

[en] DESY is presently constructing a new storage ring HERA which will provide collisions between 30 GeV electrons and 820 GeV protons. Experimentation is scheduled to begin in 1990. HERA offers exciting and unique physics opportunities. The collisions are equivalent to the scattering of 52000 GeV electrons on stationary protons and lead to a c.m. energy of s^1/2=314 GeV. A further dimension is added by the possibility to have longitudinally polarized electrons or positrons. We shall discuss a few reactions that are exemplary for the type of experiments possible at HERA

[en] We review information on the top quark mass from a study of its contributions to i) radiative corrections to the standard electroweak model, ii) the ratio of W and Z events in pantip interactions, iii) B-antiB mixing, and iv) prompt lepton cross sections measured in pantip collider experiments. We conclude that 25 GeV < m_t < 200 GeV and that, contrary to popular belief, there are no arguments compelling enough to discourage searching any mass window within that range