Nonextensive quasiparticle description of QCD matter

TL;DR

This paper explores a nonextensive quasiparticle model for QCD matter, incorporating nonextensivity parameter q to better describe small, violent collision systems where traditional Boltzmann-Gibbs statistics fail.

Contribution

It introduces a nonextensive quasiparticle framework for QCD matter, separating dynamical effects from nonextensive statistical effects using effective fugacities and the parameter q.

Findings

Separation of dynamics and nonextensivity effects in QCD matter models

Enhanced understanding of nonextensive effects in small collision systems

Framework applicable to phenomenological modeling of QCD matter

Abstract

The dynamics of QCD matter is often described using effective mean field (MF) models based on Boltzmann-Gibbs (BG) extensive statistics. However, such matter is normally produced in small packets and in violent collisions where the usual conditions justifying the use of BG statistics are not fulfilled and the systems produced are not extensive. This can be accounted for either by enriching the original dynamics or by replacing the BG statistics by its nonextensive counterpart described by a nonextensivity parameter $q\neq 1$ (for $q \to 1$ one returns to the extensive situation). In this work we investigate the interplay between the effects of dynamics and nonextensivity. Since the complexity of the nonextensive MF models prevents their simple visualization, we instead use some simple quasi-particle description of QCD matter in which the interaction is modelled phenomenologically by some effective fugacities, $z$. Embedding such a model in a nonextensive environment allows for a well-defined separation of the dynamics (represented by $z$) and the nonextensivity (represented by $q$) and a better understanding of their relationship.