Hot drops: The mean field approximation for statistical and collective phenomena in nuclei

Abstract
A summation of selected graphs in the perturbation expansion for the statistical operator and the operator of state leads to a simplified equation of motion for the nuclear many-body problem. It contains as a special limit the time-dependent Hartree-Fock and the quantum-statistical master equation. In a pictorial way one could label the approach as "Hartree-Fock plus collision terms." The formalism allows one to understand the progression of the nucleus from the boiling of the particle-hole excitations to the collective state of motion. The work is restricted presenting the formalism. Various applications are possible and indicated, but apart from an illustrative example no concrete comparison with the experiment has been performed.