Medium influence of the nucleon nucleon cross section on the fragmentation

Based on an isospin dependent quantum molecular dynamics model we studied the influence of a medium correction of an isospin dependent nucleon nucleon cross section on the fragmentation at the intermediate energy heavy ion collisions. We found that the medium correction from an isospin dependent nucleon nucleon cross section increases the dependence of the fragmentation on the isospin effect of in-medium nucleon nucleon cross section, at the same time, the momentum dependent interaction (MDI) produces also an important role for enhancing the influence of the medium correction on the isospin effect of two-body collisions in the fragmentation process. In this case, the dependence of the multiplicity of intermediate mass fragments $N_{imf}$ on the isospin effect of two-body collision due to the medium correction and MDI, is a probe for extracting the information on the isospin dependent nucleon cnucleon cross section in the medium correction.