A momentum-dependent lattice Hamiltonian model for simulations of heavy ion collisions /

We investigate both directed and elliptic flow and linear momentum transfer in intermediate energy heavy ion collisions. The model that we have adapted for this work is the BUU transport equation solved with a momentum-dependent lattice Hamiltonian algorithm. We introduce an extension of this transport model that consistently takes into account the momentum-dependent in-medium modification of the nucleon-nucleon collision cross section. Comparison with linear momentum transfer data favours a soft momentum-dependent nuclear mean field of compressibility K = 215 MeV. Analysis of higher energy elliptic flow data favours a momentum-dependent over that of a momentum-independent nuclear mean field. Furthermore, we find that both the linear momentum transfer and elliptic flow data favour an in-medium nucleon-nucleon cross section over the free space cross section