Collective flow and nuclear stopping in heavy ion collisions in Fermi energy domain

The effects of the in-medium nucleon-nucleon(NN) elastic cross section on the observables in heavy ion collisions in the Fermi energy domain are investigated within the framework of the ultrarelativistic quantum molecular dynamics model. The results simulated using medium correction factors of F=σ_(NN)^(in-medium)/σ_(NN)^(free)=0.2,0.3,0.5,and the density-and momentum-dependent factor obtained from the FU3 FP1 parametrization are compared with the FOPI and INDRA experimental data. It is found that the calculations using the correction factors F=0.2 and 0.5 reproduce the experimental data(i.e.,collective flow and nuclear stopping) at 40 and 150 MeV/nucleon, respectively. Calculations with the FU3 FP1 parametrization can best fit these experimental data. These conclusions can be confirmed in both^(197)Au+^(197)Au and^(129)Xe+^(120)Sn.

The effects of the in-medium nucleon-nucleon （NN） elastic cross section on the observables in heavy ion collisions in the Fermi energy domain axe investigated within the framework of the ultraxelativistic quantum molecular dynamics model. The results simulated using medium correction factors of F=σNN^in-medium/σNN^free= 0.2,0.3, 0.5, and the density and momentum-dependent factor obtained from the FU3FP1 paxametrization are compared with the FOPI and INDRA experimental data. It is found that the calculations using the correction factors F= 0.2 and 0.5 reproduce the experimental data （i.e., collective flow and nuclear stopping） at 40 and 150 MeW nucleon, respectively. Calculations with the FU3FP1 parametrization can best fit these experimental data. These conclusions can be confirmed in both ^197Au ＋^197 au and ^129Re ＋^120 Sn.