A test of a simple approximation for treating the antisymmetrisation effect in ion-ion collisions

The density matrix expansion method, together with three different effective nucleon-nucleon forces, is used to calculate the real part of the interaction potential between two 16O nuclei. The densities of the system are constructed using two different methods. In the first, a two-centre harmonic-oscillator potential is employed to construct the density and the kinetic energy density of the combined system and of the separated nuclei. In the second method, the density of the combined system is assumed to be the sum of the two separate densities and the kinetic energy densities are given approximately by the Thomas-Fermi approximation. (author)