# First order dissipative hydrodynamics and viscous corrections to the entropy four-current from an effective covariant kinetic theory

## TL;DR

This paper derives first order hydrodynamic equations and viscous corrections for a quark-gluon plasma using an effective covariant kinetic theory, highlighting the effects of medium properties and conservation laws.

## Contribution

It introduces a comprehensive framework for first order dissipative hydrodynamics with viscous corrections based on an effective kinetic theory including quark chemical potential and mass.

## Key findings

- Transport coefficients depend on medium effects and conservation laws.
- Viscous corrections significantly affect entropy density and temperature evolution.
- Pressure anisotropy and Reynolds number are characterized in boost-invariant expansion.

## Abstract

The first order hydrodynamic evolution equations for the shear stress tensor, the bulk viscous pressure and the charge current have been studied for a system of quarks and gluons, with a non-vanishing quark chemical potential and finite quark mass. The first order transport coefficients have been obtained by solving an effective Boltzmann equation for the grand-canonical ensemble of quasiquarks and quasigluons. We adopted temperature dependent effective fugacity for the quasiparticles to encode the hot QCD medium effects. The non-trivial energy dispersion of the quasiparticles induces mean field contributions to the transport coefficients whose origin could be directly related to the realization of conservation laws from the effective kinetic theory. Both the QCD equation of state and chemical potential are seen to have a significant impact on the quark-gluon plasma evolution. The shear and bulk viscous corrections to the entropy-four current have been investigated in the framework of the effective kinetic theory. The effect of viscous corrections to the entropy density have been quantified in the case of one dimensional boost-invariant expansion of the system. Further, the first order viscous corrections to the time evolution of temperature along with the description of pressure anisotropy and Reynolds number of the system have been explored for the longitudinal boost-invariant expansion.volution of temperature along with the description of pressure anisotropy of the system have also been explored.