On the general theory of nuclear non-equilibrium systems (statistical equations and 'nuclear hydrodynamics')

Abstract

The Green function method is used as the basic theory for the purpose of investigating the general structure of nuclear non-equilibrium systems. Firstly, the equations for the Green functions for Fermi systems in the real time domain are derived by application of Schwinger's variational principle for causal processes. In the second step the statistical equations (Boltzmann equation) are obtained from the first energy moments of the Green functions. By assuming a weak energy dependence of the mass operator it is then possible to generalise the time-dependent Hartree-Fock approach. The third step deals with the statistical approach to (nuclear) hydrodynamics by integrating the weighted Wigner transforms. As an example, the microscopic structure of the forces for the centre-of-mass motion of two colliding nuclei is investigated. It turns out that the 'optical' potential determines the behaviour of the systems.