CHEMICAL RELAXATION-TIMES IN A HADRON GAS AT FINITE-TEMPERATURE

The relaxation times of particle numbers in hot hadronic matter with v anishing baryon number are estimated using the ideal gas approximation and taking into account resonance decays and annihilation processes a s the only sources of particle number fluctuations. Near the QCD criti cal temperature the longest relaxation times turn out to be of the ord er of 10 fm and grow roughly exponentially to become of the order of 1 0(3) fm at temperatures around 1 00 MeV. As a consequence of such long relaxation times, a clear departure from chemical equilibrium must be observed in the momentum distribution of secondary particles produced in high energy nuclear collisions.