Isospin Effects in the Isospin Fractionation Process in Intermediate Energy HeavyIon Collisions
- Received Date: 2003-07-10
- Accepted Date: 1900-01-01
- Available Online: 2004-04-05
Abstract: Based on the isospin dependent quantum molecular dynamics model we investigated the isospin effects of isospin fractionation (N/Z)gas/(N/Z)liq from the neutron-proton ratio of colliding system and impact parameter. Here (N/Z)gasand (N/Z)liq is the neutron-proton ratio of nucleon emission for gas phase and that of fragment emission for liquid phase, respectively. Our results show that the (N/Z)gas/(N/Z)liq increases with the neutron-proton ratio of colliding systems when the system mass, incident energy and impact parameters are fixed. For the neutron-rich systems, the (N/Z)gas/(N/Z)liq depends sensitively to the form of symmetry potential and weakly on the isospin effect of the in-medium nucleon-nucleon cross section; For the neutron-poor colliding system, however, the (N/Z)gas/(N/Z)liq is not sensitive to both the form of symmetry potential and the isospin effect of the in-medium nucleon-nucleon cross section. We also found that the dependence of (N/Z)gas/(N/Z)liq on the impact parameter is not obvious. Detailed discussion and explanation for leading to these results are presented in the paper. According to these results, we propose that (N/Z)gas/(N/Z)liq can be directly compared with the experimental data to get the information about symmetry potential.