Dynamical nonextensivity or nonextensive dynamics?

Abstract

Abstract Dense matter is usually described using some kind of mean field theory (MFT) model based on Boltzmann–Gibbs (BG) extensive statistics. However, in many cases the conditions justifying the use of BG statistics are not fulfilled because the systems considered are explicitly nonextensive. In such cases one either enriches the original MFT by adding some dynamical elements violating extensivity (like, for example, long range correlations or intrinsic fluctuations), or one replaces the BG statistics by its nonextensive counterpart characterized by some nonextensivity parameter q ( q≠ 1 and for q → 1 one returns to the extensive situation). In this work, using a simple quasi-particle description of dense matter (with interaction modelled by effective fugacities, z) we discuss the mutual interplay of non-extensiveness and dynamics (i.e., q and z) and estimate the level of nonextensivity of the quark-gluon system described by lattice QCD.