arXiv subjects
Publications and source records attributed to W. Czyz.
Renyi entropies of a black hole are evaluated by counting the states of the Hawking radiation which fills a thin shell surrounding the horizon. The width of the shell is determined from its energy content and the corresponding mass defect. The Bekenstein-Hawking formula for the entropy of the black hole is correctly reproduced.
Recently suggested method of measuring Renyi entropies of multiparticle systems produced in high-energy collisions is presented in the form of a "do-list", explaining explicitely how to perform the measurement and suggesting improvements in the treatment of the data.
A model-independent lower bound on the entropy S of the multiparticle system produced in high energy collisions, provided by the Renyi entropy H_2, is shown to be very effective. Estimates show that the ratio H_2/S remains close to one half for all realistic values of the parameters.
It is pointed out that the average semi-inclusive particle phase-space density at freeze-out can be determined from the coincidence probability of the events observed in multiparticle production. The method of measurement is described and its accuracy examined.
Relation between Renyi entropies and moments of the Wigner function, representing the quantum mechanical description of the M-particle semi-inclusive distribution at freeze-out, is investigated. It is shown that in the limit of infinite volume of the system, the classical and quantum descriptions are equivalent. Finite volume corrections are derived and shown to be small for systems encountered in relativistic heavy ion collisions.
It is shown that the wounded nucleon model describes very well the recent PHOBOS data on particle production in D-Au collisions at 200 GeV. Contribution to particle production from a single wounded nucleon is determined. A two-component model is formulated and shown to account for most of the important features of the data.
An algorithm for measurement of entropy in multiparticle systems, based on recently published proposal of the present authors, is given. Dependence on discretization of the system and effects of multiparticle correlations are discussed in some detail.
The coincidence method of measuring the entropy of a system, proposed some time ago by Ma, is generalized to include systems out of equilibrium. It is suggested that the method can be adapted to analyze multiparticle states produced in high-energy collisions.
We propose to use the coincidence method of Ma to measure an entropy of the system created in heavy ion collisions. Moreover we estimate, in a simple model, the values of parameters for which the thermodynamical behaviour sets in.
Forward differential cross-section for diffraction dissociation of virtual photons on nucleon target is calculated in the QCD dipole picture. The numerical estimates are presented and discussed.
We discuss the possibility to measure entropy of the system created in heavy ion collisions using the Ma coincidence method.
Compact and well defined formulae for the shadow of the virtual photon interacting with a large nucleus at small $x_{Bj}$ are given in the QCD dipole picture. Two classes of contributions are considered: (a) quasi-elastic interaction of the $q\bar{q}$ dipole and (b) multi-pomeron coupling.
In the framework of the dipole picture of the BFKL pomeron we discuss a few possibilities of calculating the total $γ^{\star}γ^{\star}$ cross section of the virtual photons. We argue that the existing successful fits of the dipole picture formulae to the measured structure functions $F_2(Q^2,x)$ favor one of the possible extensions of the dipole picture of the BFKL pomeron formulated recently by one of us.