Non-extensive statistics, fluctuations and correlations in high-energy nuclear collisions

Abstract

Starting from the experimental evidence that high-energy nucleus-nucleus collisions cannot be described in terms of superpositions of elementary nucleon-nucleon interactions, we analyze the possibility that memory effects and long-range forces imply a nonextensive statistical regime during high energy heavy ion collisions. The relevance of these statistical effects and their compatibility with the available experimental data are discussed. In particular we show that theoretical estimates, obtained in the framework of the generalized nonextensive thermostatistics, can reproduce the shape of the pion transverse mass spectrum and explain the different physical origin of the transverse momentum correlation function of the pions emitted during the central Pb+Pb and during the p+p collisions at 158 A GeV.

Generalized classical and quantum dynamics within a nonextensive approach

“…Because of the growing interest to high energy physics applications of nonextensive thermostatistics [6], in this Section we want to study the formulation of the relativistic nonextensive kinetic equations. Let us start defining the basic macroscopic variables in the language of relativistic kinetic theory.…”

“…In fact, the quark-gluon plasma close to the critical temperature is a strongly interacting system [6]. For such a system, the colorCoulomb coupling parameter of the QGP can be defined, in analogy to the classical plasma, as…”

Nonextensive statistical effects on the relativistic nuclear equation of state

“…1, we report the obtained hadronic EOS: pressure as a function of the baryon number density (in units of the nuclear saturation density ρ 0 = 0.16 fm −3 ) for different values of q. Because of previous phenomenological studies in heavy-ion collisions have brought to values of q greater than unity [2], we concentrate our analysis to q > 1. The results are plotted at the temperature T = 100 MeV and at fixed value of Z/A = 0.4.…”

“…In particular, recently, many authors outline the possible connection to the nonextensive statistical framework with nuclear and high energy physical applications [2,3,4,5,6,7]. The aim of this work is to generalize the basic concepts of the nonextensive statistical mechanics to the relativistic regime and to investigate, through the obtained relativistic thermodynamic relations, the relevance of nonextensive statistical effects on the hadronic and on the quark-gluon plasma (QGP) equation of state (EOS).…”

Charged-hadron production in the three-sources RDM at LHC energies

“…Even in the presence of expansion, drift and diffusion coefficients are related through a dissipationfluctuation theorem in the nonlinear version [1,1,9] of the model where a nonextensivity parameter q implicitly accounts for the effect of long-range interactions that are considered to cause the collective behaviour. In the linear model, expansion is treated explicitly [8].…”