Impact of nonextensivity on the transport coefficients of strongly interacting QCD matter

TL;DR

This study investigates how nonextensive Tsallis statistics influences the transport properties of strongly interacting QCD matter, revealing that nonextensivity significantly alters viscosities and conductivities, with implications for understanding quark-gluon plasma behavior.

Contribution

The paper introduces a nonextensive parameter into the Polyakov chiral SU(3) model to analyze its effects on transport coefficients, providing new insights into nonextensive effects on QCD matter.

Findings

Nonextensivity enhances shear viscosity and electrical/thermal conductivities.

Bulk viscosity decreases with increasing nonextensivity.

Transport coefficients vary with chemical potential and temperature.

Abstract

Tsallis nonextensive statistics is applied to study the transport coefficients of strongly interacting matter within the Polyakov chiral SU(3) quark mean field model (PCQMF). Nonextensivity is introduced within the PCQMF model through a dimensionless $q$ parameter to examine the viscous properties such as shear viscosity ($\eta$), bulk viscosity ($\zeta_b$), and conductive properties, including electrical conductivity ($\sigma_{el}$) and thermal conductivity ($\kappa$). Additionally, some key thermodynamic quantities relevant to the transport coefficients, like the speed of sound ($c_{sq}^2$) and specific heat at constant volume ($c_{vq}$), are calculated. The temperature dependence of the transport coefficients is explored through a kinetic theory approach with the relaxation time approximation. The results are compared to the extensive case where $q$ approaches 1. The nonextensive $q$ parameter is found to have a significant effect on all transport coefficients. We find that the nonextensive behaviour of the medium enhances both specific shear viscosity $\eta/s_q$ as well as conductive coefficients $\sigma_{el}/T$ and $\kappa/T^2$. In contrast, the normalised bulk viscosity $\zeta_b/s_q$ is found to decrease as the nonextensivity of the medium increases. We have also studied the transport coefficients for finite values of chemical potentials. The magnitude of $\eta$, $\sigma_{el}$, and $\kappa$ increases at lower temperatures while $\zeta$ is found to decrease for systems with non-zero chemical potential.