Nonequilibrium quasi-classical effective meson gas

We treat a gas of interacting relativistic effective mesons (similar to those produced in a heavy-ion collision), regarded as a nonequilibrium statistical system. The large number of degrees of freedom gives rise to statistical features. We suppose large occupation numbers, temperature somewhat below typical critical temperatures and the quasi-classical regime. At the initial time t0, the gas is off-equilibrium. We analyze the time evolution of the quasi-classical effective meson gas for t>t0 by using a new moment method. Long-time approximations, which could yield the approach to global thermal equilibrium, are presented.