On the Damping Rate of a Fast Fermion in Hot QED
  The self-consistent determination of the damping rate of a fast moving fermion in a hot QED plasma is reexamined. We argue how a detailed investigation of the analytic properties of the retarded fermion Green's function motivated by the cutting rules at finite temperature may resolve ambiguities related to the proper definition of the mass-shell condition. 
R. Baier (Bielefeld) and R. Kobes (LAPP)