  The quantum kinetics of photons is studied directly in real time by
implementing the dynamical renormalization group. In contrast to conventional
approach, the dynamical renormalization group method consistently includes
off-shell (energy non-conserving) effects and accounts for time-dependent
collisional kernel. To lowest order we find that in the relaxation time
approximation the semihard photon distribution function relaxes with a power
law.

High Energy Physics - Phenomenology;Nuclear Theory