Relativistic features of the effective interaction in heavy-ion collisions

The self-energy of a nucleon in a heavy-ion collision depends on the relative velocity and the density of the colliding nuclei. We estimate the scalar and vector self-energies by parametrizing a non-relativistic Brueckner-HF calculation for a system of two colliding symmetric nuclear-matter streams in terms of a relativistic mean field approximation for this system. We therefore evaluate the effective interaction in colliding nuclear matter by calculating the Brueckner G-matrix for a realistic NN interaction and we discuss the resulting single-particle potential. The single-particle energies are then analyzed in terms of the relativistic mean field approximation thereby determining the scalar and vector self-energy. From these we calculate effective coupling parameters by dividing through the corresponding densities. These coupling parameters, which then effectively contain the momentum dependence, correlations and exchange, are discussed as functions of relative momentum and density. They could be used to improve kinetic calculations of relativistic heavy-ion collisions. (orig.)