COLLECTIVE EXCITATIONS OF MASSIVE DIRAC PARTICLES IN A HOT AND DENSE MEDIUM

The one-loop dispersion relation which defines the collective excitati ons of massive Dirac particles in a hot and dense quark-gluon medium i s obtained in the high-temperature limit far the case m much less than gT and is solved explicitly for all \q\ when mu=0. Four well-separate d spectrum branches (quasi-particle and quasi-hole excitations) are fo und, and their behaviors for small and large \q\ are investigated. All calculations are performed using the temperature Green function techn ique and fixing the Feynman gauge. The gauge dependence of the spectra found is briefly discussed. (C) 1998 American Institute of Physics. [ S0021-3640(98)00101-7].