EFFECTIVE THEORY FOR REAL-TIME DYNAMICS IN HOT GAUGE-THEORIES

For a high temperature non-Abelian plasma, we reformulate the hard the rmal loop approximation as an effective classical thermal field theory for the soft modes. The effective theory is written in local Hamilton ian form, and the thermal partition function is explicitly constructed . It involves an ultraviolet cutoff which separates between hard and s oft degrees of freedom in a gauge-invariant way, together with counter terms which cancel the cutoff dependence in the soft correlation funct ions. The effective theory is well suited for numerical studies of the non-perturbative dynamics in real time, in particular, for the comput ation of the baryon number violation rate at high temperature. (C) 199 8 Elsevier Science B.V. All rights reserved.