IN-MEDIUM EFFECTS IN THE DESCRIPTION OF HEAVY-ION COLLISIONS WITH REALISTIC NN INTERACTIONS

The simulations of Ca-40 + Ca-40 and Nb-93 + Nb-93 collisions at E(lab) = 400 MeV/u have been performed within the quantum molecular dynamics approach using both the phenomenological Skyrme forces and the Brueckner G-matrix potential as the in-medium NN interaction. The influence of the density and momentum dependence of the interaction on the time evolution of heavy-ion collisions is studied in detail. We found that the momentum dependence of the in-medium interaction strongly affects the density and temperature of the nuclear matter formed during collisions. Most of the results obtained for different observables are shown to be more sensitive to the momentum dependence of the interaction than to the nuclear equation of state. The strong repulsive G-matrix potential acting between nucleons with large relative momenta in the low-density region leads to an appreciably larger transverse momentum transfer and a smaller number of NN collisions compared with those obtained using the Skyrme potentials. Results obtained with the medium-dependent G-matrix NN cross section and those obtained with the phenomenological NN cross section parametrized by Cugnon et al. for the collision term are also compared.