Transport coefficients in Polyakov quark meson coupling model: a relaxation time approximation

TL;DR

This paper calculates shear and bulk viscosities and thermal conductivity of hot, dense matter using the Polyakov quark meson model, revealing critical behavior near the phase transition.

Contribution

It introduces a detailed estimation of transport coefficients within the Polyakov quark meson model using the relaxation time approximation, incorporating energy-dependent relaxation times from scattering processes.

Findings

Shear viscosity to entropy ratio shows a minimum at the critical temperature.

Thermal conductivity coefficient exhibits a minimum at the transition.

Bulk viscosity to entropy density peaks at the phase transition.

Abstract

We compute the transport coefficients, namely, the coefficients of shear and bulk viscosities as well as thermal conductivity for hot and dense matter. The calculations are performed within the Polyakov quark meson model. The estimation of the transport coefficients is made using the Boltzmann kinetic equation within the relaxation time approximation. The energy dependent relaxation time is estimated from meson meson scattering, quark meson scattering and quark quark scattering within the model. In our calculations, the shear viscosity to entropy ratio and the coefficient of thermal conductivity show a minimum at the critical temperature, while the ratio of bulk viscosity to entropy density exhibits a peak at this transition point.The effect of confinement modelled through a Polyakov loop potential plays an important role in the estimation of these dissipative coefficients both below and above the critical temperature.