Transport coefficients in the Polyakov quark meson coupling model: A quasi particle approach

TL;DR

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

Contribution

It introduces a quasi-particle approach with energy-dependent relaxation times derived from scattering processes within the Polyakov quark meson model.

Findings

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

Thermal conductivity coefficient shows 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 loop extended 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.