We review results on hadron multiplicities in high energy particle collisions. Both theory and experiment are discussed. The general procedures used to describe particle multiplicity in Quantum Chromo-dynamics (QCD) are summarized. The QCD equations for the generating functions of the multiplicity distributions are presented both for fixed and running coupling strengths. The mean multiplicities...

We derive classically an expression for a hadron width in a two-phase region of hadron gas and quark-gluon plasma (QGP). The presence of QGP gives hadrons larger widths than they would have in a pure hadron gas. We find that the φ width observed in a central Au+Au collision at √ s = 200 GeV/nucleon is a few MeV greater than the width in a pure hadron gas. The part of observed hadron widths due ...

Total and differential cross sections for high energy and small momentum transfer elastic hadron-hadron scattering are studied in QCD using a functional integral approach. The hadronic amplitudes are governed by vacuum expectation values of lightlike Wegner-Wilson loops, for which a matrix cumulant expansion is derived. The cumulants are evaluated within the framework of the Minkowskian version...

The charge and matter density distributions encode detailed information on hadron structure. In the non-relativistic limit both charge and matter density distributions reduce to the square of the wave function. Therefore differences between them give a measure of relativistic effects. Hadron deformation can be searched via the matter density distribution as well as via the charge density distri...

The finite corrections of order % in perturbative QCD to the cross-sections for semi-inclusive hadron production from deep inelastic leptonhadron scattering and electron-positron annihilation are calculated. We define the effective quark fragmentation functions via e § e--* hadron + X including the finite terms in order to estimate these corrections for the reactions lepton + hadron --* lepton ...

The role played by colorless gluon-clusters in the optical-geometrical approach to high-energy inelastic diffractive scattering is discussed. A simple analytical expression for the t-dependence of the integrated single diffractive cross section (t is the four-momentum transfer squared) is derived. Comparison with the existing data and predictions for future experiments are presented. ∗e-mail ad...