R. Baier et al., DYNAMICAL SCREENING FOR HARD PHOTON PRODUCTION AWAY FROM EQUILIBRIUM, Progress of theoretical physics. Supplement, (129), 1997, pp. 119-123
The production of hard; photons from a quark-gluon plasma away from eq
uilibrium is investigated in the framework of closed time-path thermal
field theory. Additional off-equilibrium contributions associated wit
h pinch singularities are taken into account. Dynamical screening is s
hown to provide a self-consistent infrared cut-off making the thermal
production rate well defined in this generalized situation as well.