Cumulants of QCD Multiplicity Distributions in Small Phase Space Bins

It is shown that, as functions of their rank, cumulants of QCD multiplicity distributions in small phase space bins possess the quasi- oscillating behavior similar to that found for them in the total rapidity range. First minimum moves to lower ranks for smaller bins. For the total rapidity range, it moves to higher ranks with energy increase. The running property of the QCD coupling constant is in charge of these effects which can be verified in experiment.Comment: 7 pages, no Figs, preprint IP-ASTP-19; FIAN-TD 94/

The medium in heavy-ion collisions

The nuclear index of refraction, the density of partons, their free path length and energy loss in the matter created in heavy-ion collisions at RHIC are estimated within the suggestion that the emission of Cherenkov gluons is responsible for the observed two-bump structure of the angular distribution of hadrons belonging to the companion (away-side) jet.Comment: 3 pages, 1 Figur

On distribution of number of trades in different time windows in the stock market

Properties of distributions of the number of trades in different intraday time intervals for five stocks traded in MICEX are studied. The dependence of the mean number of trades on the capital turnover is analyzed. Correlation analysis using factorial and $H_q$ moments demonstrates the multifractal nature of these distributions as well as some peculiar changes in the correlation pattern. Guided by the analogy with the analysis of particle multiplicity distributions in multiparticle production at high energies, an evolution equation relating changes in capital turnover and a number of trades is proposed. We argue that such equation can describe the observed features of the distribution of the number of trades in the stock market.Comment: LaTeX, 6 figure

Cherenkov Glue in Opaque Nuclear Medium

The spectrum of Cherenkov gluons is calculated within the framework of in-medium QCD. It is compared with experimental data on the double-humped structure around the away-side jet obtained at RHIC. The values of the real and imaginary parts of the nuclear permittivity are obtained from these fits. It is shown that accounting for an additional smearing due to resonance-like production of final hadrons allows to achieve an agreement with experimental data

Hadron Multiplicities

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 Chromodynamics (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 of gluon and quark jets, their ratio, higher moments, and the slopes of multiplicities as a function of energy scale, are among the main global features of multiplicity for which QCD results exist. Recent data from high energy e+e- experiments, including results for separated quark and gluon jets, allow rather direct tests of these results. The theoretical predictions are generally quite successful when confronted with data. Jet and subjet multiplicities are described. Multiplicity in limited regions of phase space is discussed in the context of intermittency and fractality. The problem of singularities in the generating functions is formulated. Some special features of average multiplicities in heavy quark jets are described.Comment: 140 pages, 33 figures, version for Physics Report

Measuring Hadronization Length in e^+ e^- \rightarrow K^0 {\bar{K}}^0 \gamma

We propose to study the space-time picture of hadronization by looking at the angular distribution of photons emitted in the process e^+ e^- \rightarrow K^0 {\bar{K}}^0 \gamma at DA{\Phi}NE energies. it is shown that the angular distributions are quite sensitive to the hadronization length.Comment: 5 pages, CERN-TH-7200/94, BI-TP 94/04, March 199

Soft and hard processes in QCD

QCD equations for the generating functions are applied to separate soft and hard jets in $e^+e^-$-processes of multiparticle production. The dependence of average multiplicities and higher moments of multiplicity distributions of particles created in a "newly born" soft subjets on the share of energy devoted to them is calculated in fixed coupling gluodynamics. This dependence is the same as for the total multiplicity up to a constant factor if soft jets are defined as those carrying out a fixed share of initial energy at all energies. The constant factor depends on this share in a non-trivial way. Other definitions are also proposed. The relation between these quantities for soft and hard processes is discussed.Comment: 6 pages, no Figures, LATEX, more detailed discussion of definitions and proposals for experiment is give

The background for Cherenkov gluons at RHIC and LHC energies

The pseudorapidity distribution of centers of dense isolated groups of particles in HIJING model is determined. It can be considered as the background for Cherenkov gluons. If peaks over this background were found in experiment, they would indicate the onset of new collective effects.Comment: 4 pages, 2 figures, uses espcrc1.sty; QM 2005 contributio

High ET_T jets and double scattering

The recently found excess of high E$_T$ jets over current QCD predictions is attributed to gluon radiation at double scattering process inside a nucleon. The order of magnitude estimate of the cross section fits experimental findings rather well. The specific features of the process are discussed. Various similar hadronic effects related to the short radiation length are described.Comment: 6 pages, plain LaTe

Ring-like events: Cherenkov gluons or Mach waves?

Similar to electromagnetic forces, strong interactions might induce such collective effects as Cherenkov and Mach waves. Their conical structure would be responsible for specific ring-like events. The theoretical and experimental arguments in favor of these phenomena are discussed and their most important features are described.Comment: 12 pages, 5 figures, LATEX, misprint correcte