Dirac-Brueckner mean fields and the effective Dirac-Hartree-Fock interaction in nuclear matter

Our objective is to include Fock exchange terms, and thus the pion, in a Dirac description of nuclear matter and to determine a density-dependent Dirac-Hartree-Fock meson exchange interaction that is hopefully less density-dependent than a typical Hartree one. We begin by performing extended self-consistent nuclear matter Dirac-Brueckner calculations over a wide range of densities and asymmetries. We maintain the momentum dependence of the Brueckner mean fields in the hope of fitting it with the momentum dependence of the effective Dirac-Hartree-Fock mean fields. To improve the description of the Brueckner mean fields within a Hartee-Fock approximation, we include contact terms in the interaction.