[en] Recent experimental results on photo- and hadroproduction of heavy flavor particles are reviewed. After a short introduction on the recent advances in the theoretical ideas describing the production of heavy flavors, current experimental techniques used in heavy flavor search in fixed target experiments are briefly discussed. New results on the production characteristics, production cross section and on the A-dependence of the open and hidden charm cross section are presented

[en] During the 1988/1989 run at the Fermilab Tevatron, the CDF detector collected ≅ 4.1 pb^-1 of p bar p data at √s = 1.8 TeV. The main goals of this run being physics at high p_t, the CDF trigger was tuned for maximizing signals from Z⁰s, Ws, t-quarks, and etc. As such, compared to the high pt physics, the b-physics program was of secondary importance other than that which would be used for background calculations. Also, CDF had no vertex chamber capability for seeing displaced vertices. However, significant b-quark physics results are evident in two data samples: (1) inclusive electrons; (2) inclusive J/ψ where J/ψ → μ⁺μ^-. In this paper, the author will try to specify the goals for b-physics using the inclusive electrons and J/ψ signals for the 1988/89 data set. He will then provide a brief look at the data, and will finish with some highly speculative guesses as to whether or not experiments at the Tevatron which look for CP violation in the b sector are possible

[en] In the past few years a good deal of enthusiasm has arisen in the US, Europe and Asia for B-Factories. In these machines electrons and positrons are collided with center-of-mass energies at or near the Υ(4s) resonance, with unprecedented high luminosities, to produce copious fluxes of B-mesons. The object is to make high-precision studies of the CP non-conserving B decays. Various colliding-beam configurations have been suggested including both linear colliders and storage rings, but one scheme has emerged as generally preferable to the others. It is the asymmetric storage ring system-asymmetric in the sense that the two beam energies are markedly different and the center of mass is moving in the direction of the higher energy beam. With this arrangement the decaying B-mesons fly off from the interaction region in the same direction, and the time-order of their decays can be deduced from the locations of their decay vertices. These B-Factories present the accelerator builder with two main challenges: to achieve luminosity far beyond that attained in existing storage rings and to do it in the unexplored arena of unequal beam energies. Fortunately the means of meeting these challenges appear to be in hand on the basis of the present understanding of the accelerator physics of colliding-beam storage rings. The problems have been studied in several laboratories in Europe, Japan, the US and the USSR, and the solutions devised in those studies have converged in their general features. A B-Factory will consist of two separate storage rings with a common collision region; each ring will carry what it, by today's standards, high circulating beam currents, and as a consequence, the vacuum chambers will be very well-cooled and strongly vacuum-pumped; and mechanical designs of the interaction regions will be quite complicated, but also quite feasible

[en] The author reviews the first round of QCD studies at the e⁺e^- collider LEP, which started operating towards the end of last year. These studies at the peak of the Z⁰ resonance have proven to be extremely rewarding, not only because of the large statistics available due to the high resonance cross section, but also because of the higher center of mass energy, which allows a much cleaner study of events with multiple jets. For example, 20% of the events show a clean 3-jet structure in which the least energetic jet has an average energy of 20 GeV. Such events originate from quark-antiquark-gluon (q bar qg) states, in which the least energetic jet is usually the gluon jet. Therefore, at LEP energies the gluon jets are considerably healthier than at the PEP and PETRA colliders, where the energies were typically three times lower. The higher jet energy gives a better collimation of the jets and therefore a better jet axis determination and separation between the jets. This improves many QCD studies, especially the study of gluon jets and the angular correlations in 4-jet events, from which one can hope to isolate the triple gluon vertex contribution. This gluon self interaction is the hallmark of the non-abelian character of QCD and is thought to be responsible for the confinement of quarks inside the nuclei. The topics to be discussed here are: intermittency; charged multiplicity and rapidity distribution; comparison with fragmentation models; soft gluon coherence; jetmultiplicity studies and the determination of α, determination of α, from the asymmetry in energy-energy correlations; and search for the triple gluon vertex

[en] The CHARM2 detector has been designed to obtain a precision determination of the electro-weak mixing parameter sin 2θ_W via a measurement of the ratio of the cross section of the purely leptonic neutral current processes ν_μ + e → ν_μ + e and bar ν_μ + e → bar ν_μ + e. The main difficulties for the study of these processes come from that very small value of the cross section and from the high level of background. The single electron events produced in the ν_μ - e scattering must be extracted from the deep inelastic neutrino nucleon scattering ones that have a three order of magnitude higher rate. To match these requirements CHARM2 [2] has been built as a high mass, low Z, high granularity, sampling calorimeter (total mass 692 tons). The detector has been exposed to the CERN WB neutrino beam starting from 1987. Neutrino and antineutrino runs have been alternated every few days to ensure uniform detector behavior and a total of 2 x 10 19 protons on target have been collected in 87,88,89,90 runs. The analyses that will be presented here refer to 87,88,89 data (75% of the total statistics). The low Z of the target material allows a precise measurement of muon direction, while the high granularity of the detector makes possible a detailed study of vertex activity. These characteristics of the CHARM2 calorimeter together with the muon momentum information have allowed the author to study two leptonic processes in which the neutrino electron interaction gives rise to final states containing only muons and precisely (1) Inverse muon decay ν_μ + e - → μ - +ν_e (2) Muon pair production in the electromagnetic field of a nucleus. ν + A → ν + μ + +μ - +A. This process, usually called neutrino trident production, can be seen from the point of weak interactions as ν_μμ elastic scattering

[en] Some recent results are reported from the ARGUS experiment, operated at the e⁺e^- storage ring DORIS II at DESY. In an updated analysis of semileptonic b → u decays direct evidence for such transitions was obtained through reconstruction of a complete event. A study of the lepton energy spectra in τ^- → e^- ν bar ν and τ^- → μ ν bar ν decays yielded a value for the Michel parameter which is in good agreement with a standard V - A coupling at the τ-ν_τ-W vertex. A parity violating asymmetry was measured in τ decays into three charged pions which shows that the τ neutrino has negative helicity. The Micro Vertex Drift Chamber was installed as a new hardware component of the ARGUS detector. Initial results concerning backgrounds and chamber performance are presented

[en] The bottom quark should need no introduction. Other than the undiscovered top quark, it is by far the most fashionable of the six. There is good reason for this. It is bottom-quark behavior which holds out the most hope of measuring and understanding some of the most fundamental and delicate parameters of the standard model - those having to do with the origin of electroweak mixing - and thereby in all probability also the origin of quark mass. Also interwoven into this is the subject of CP violation, and its proposed interpretation in terms of electroweak mixing. In this section the author shall review the basics of electroweak mixing and how it is impacted by the study of b-quark properties. There are by now many lecture series and workshop proceedings devoted to this topic, the author will not try to be comprehensive, but only hit some highlights

[en] These lectures survey why the top quark may be unusually interesting if its mass is large. Perhaps the large mass is related to a fundamental role of the top quark. Perhaps it will have non-Standard Model decays, or be sensitive to some new physics

[en] Two experiments will be discussed, NA31 and CP-LEAR, The main results of NA31 on CP- and CPT-violation will be reviewed. A recent measurement of the decay K_L → π degree γγ, which has some relevance for CP-violation in the decay K_L → π degree e⁺e^-, will be presented in some detail, and a new proposal for a more precise measurement of ε'/ε will be outlined. For CP-LEAR the aims of the experiment and a brief status report will be given

[en] To go beyond the LEP 1 program, one can (1) increase the c.m. energy; (2) increase the luminosity, an option technically related to the previous one; (3) increase the sensitivity to possible deviations from the Standard Model by polarizing the beams. These upgrades open up the way to many possibilities for physics concerning accurate measurements as well as searches for the new effects. They also require, from the theoretical and experimental points of view, several improvements and changes. These various topics and their interrelatedness are reviewed and discussed