"This volume presents the experimental and theoretical methods of studying soft interaction physics in high energy collisions. The topics include: dynamical and Bose-Einstein correlations, multiplicity fluctuation, soft photons, disoriented chiral condensate, self-similarity and self-affine behaviors, wavelet analysis, intermittency, chaos, and phase transition."--Publisher's website.

During more than 10 years, from 1989 until 2000, the LEP accelerator and the four LEP experiments, ALEPH, DELPHI, L3 and OPAL, have taken data for a large amount of measurements at the frontier of particle physics. The main outcome is a thorough and successful test of the Standard Model of electroweak interactions. Mass and width of the Z and W bosons were measured precisely, as well as the Z and photon couplings to fermions and the couplings among gauge bosons. The rst part of this work will describe the most important physics results of the LEP experiments. Emphasis is put on the properties of the W boson, which was my main research eld at LEP. Especially the precise determination of its mass and its couplings to the other gauge bosons will be described. Details on physics effects like Colour Reconnection and Bose-Einstein Correlations in W-pair events shall be discussed as well. A conclusive summary of the current electroweak measurements, including low-energy results, as the pillars of possible future ndings will be given. The important contributions from Tevatron, like the measurement of the top quark and W mass, will round up the present day picture of electroweak particle physics.

We have studied hadronic final states produced in the decays of Z bosons using the Mark II detector at SLC. We have measured the distributions of global shape parameters, inclusive charged particle distributions, charge particle multiplicity and jet multiplicity. The results are compared to predictions of QCD-based models optimized at the PEP energy. The data and models agree within the present statistical precision. We have also investigated a new method to determine the QCD scale parameter [Lambda]{sub {ovr MS}} using differential jet multiplicity. 9 refs., 5 figs.

Searches for events with new particle topologies in 455 hadronic Z decays with the Mark 2 detector at SLC are presented. 95% confidence level lower limits of 40.7 GeV/c2 for the top quark mass and 42.0 GeV/c2 for the mass of a fourth generation charge - 1/3 quark, regardless of decay mode, are obtained. For a fourth generation sequential Dirac neutrino?4 mass up to 43 GeV/c2. Decays of the Z boson to a pair of non-minimal Higgs bosons (Z → H{sub s}°H{sub p}°), where one of them is relatively light ({approx lt} 10 GeV/c2), are also considered. Limits are obtained on the ZH{sub s}°H{sub p}° coupling as a function of the Higgs boson masses. 11 refs., 2 figs., 2 tabs.