The effects of mean field and two-body collision on the radial expansion energy

The expansion energy has been studied by using BUU model based on the Skyrme interaction to obtain the information of equation of state. The effects of the radial expansion energy on the mean field and two-body collision have been discussed. The results are that in intermediate energy heavy ion collisions the radial expansion energy is sensitive to the effective mass m* and insensitive to the incompressibility. The reasonable effective mass m* 0.8 m is obtained by comparison of the expansion energy with the experiment. The cross section has a little influence on the expansion energy and the effect of the cross section on the expansion energy increases with increasing beam energy. (orig.)