A QUANTUM KINETIC-EQUATION FOR FERMI SYSTEMS INCLUDING 3-BODY CORRELATIONS

A single-time quantum transport equation, which includes effects beyon d the quasiparticle approximation. is derived for Fermi systems in the framework of nonequilibrium real-time Green's functions theory. Terna ry correlations are incorporated in the kinetic description via a clus ter expansion for the self-energies (e.g., the transport vertex and th e width) truncated at the level of three-body scattering amplitudes. A finite temperature/density formulation of the three-body problem is g iven. Corresponding three-body equations reduce to the well-known Fadd eev equations in the vacuum limit. In equilibrium the equation uf stat e contains virial corrections proportional to the third quantum virial coefficient. (C) 1998 Academic Press.