Nuclear matter density, collision number and entropy in dynamics process of intermediate high energy heavy ion collision

The nuclear matter density, collision number and entropy in the dynamic process of heavy ion collision 40Ca + 40Ca at EL = 400 MeV/A for very central collision were calculated. The results show that the nuclear spatial density distributions depend mainly on the mean field but rarely on the nucleon-nucleon collisions. The density distribution in the momentum space, collision number and entropy are influenced by the mean field and nucleon-nucleon collisions, especially the medium effects