Influence of Non-extensivity on the drag and diffusion coefficients of hadronic matter

TL;DR

This paper explores how non-equilibrium effects, modeled by Tsallis nonextensive statistics, influence the transport coefficients of hadrons in a thermal bath, revealing temperature, nonextensivity, and composition dependencies.

Contribution

It introduces a nonextensive statistical framework to analyze hadronic transport coefficients, accounting for deviations from thermal equilibrium in heavy ion collision environments.

Findings

Drag and diffusion coefficients increase exponentially with temperature and nonextensivity parameter q.

Spatial diffusion decreases with temperature, q, and hadronic mass cutoff.

Heavier mesons relax later than lighter ones in the hadronic medium.

Abstract

In this work, we investigate the drag and diffusion coefficients of various hadrons propagating through a hadronic thermal bath by employing the Fokker Planck equation within the framework of Tsallis nonextensive statistics. The nonextensive parameter $q$ accounts for the deviation from equilibrium and provides a more realistic description of the medium that is not perfectly thermalized. The hadronic bath, consisting of various mesonic and baryonic species, is characterized by different mass cutoffs that control the spectral composition of the medium. Our analysis shows that both the drag $F$ and momentum diffusion coefficients $\Gamma$ increases exponentially with temperature and increases systematically with increasing $q$ and mass cutoff. The spatial diffusion coefficient $D_x$ exhibits a decreasing trend with temperature $T$, $q$ and mass cutoff which highlights the significant influence of nonequilibrium effects and hadronic composition on the transport behaviour of hadrons, offering valuable insights into the thermal and dynamical properties of the hadronic phase preceding freezeout in heavy ion collisions. Additionally, we have studied the relaxation time of heavy mesons such as $D_0$, $J/\psi$ and $\Upsilon$. We found that the heavier mesons relaxed later in comparison to the lighter mesons in the hadronic medium.