Transport Coefficients in Quasi-particle Models

Abstract

We study the non-equilibrium properties of a dynamical fluid composed of quasi-particles whose mass is temperature and charge chemical potential dependent, in kinetic theory under the relaxation time approximation. In particular we calculate the scaling behaviour of bulk viscosity 'ζ' near the QCD chiral phase transition in the 3d O (2) universality class. It is found that the bulk viscosity 'ζ' does not show a divergent behaviour near the QCD chiral phase transition. This scaling behaviour of 'ζ' prevails in the presence of Gold-stone modes that arise due to the explicit breaking of continuous O (4) symmetry. On contrary these modes have a significant effect on the scaling behaviour of specific heat C V which diverges at the critical temperature T C .