Dynamical screening in hot systems away from (chemical) equilibrium

Abstract

Within the Closed Time Path Formalism of Thermal Field Theory we calculate the hard photon emission rate as well as the collisional energy-loss rate for a quark-gluon plasma away from chemical equilibrium. Mass singularities are shown to be dynamically screened within HTL-resummed perturbation theory also away from equilibrium. Additional (pinch) singularities are absent and well defined results are obtained.

Comments: Talk given at the Japanese Workshop on Thermal Quantum Field Theories and their Applications, Kyoto, Japan, 25.-27. August 1999, 6 pages