We investigate the effect of the medium on the thermal conductivity of a pion gas out of chemical equilibrium by solving the relativistic transport equation in the Chapman-Enskog and relaxation time approximations. Using an effective model for the $\pi \pi$ cross section involving $\rho$ and $\sigma$ meson exchange, medium effects are incorporated through thermal one-loop self-energies. The temperature dependence of the thermal conductivity is observed to be significantly affected.

• Received 5 September 2013

DOI:https://doi.org/10.1103/PhysRevD.89.054013