Probing of the Isospin-Dependent Mean Field and Nucleon-Nucleon Cross Section in a Medium by Nucleon Emissions
LIU Jian-Ye1,2,3,4, XING Yong-Zhong1,2, GUO Wen-Jun3
1Institute for Theory of Modern Physics, Tianshui Normal University, Tianshui 741000
2Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000
3Institute of Modern Physics, Chinese Academy of Sciences, PO Box 31, Lanzhou 730000
4CCAST (Word Laboratory), PO Box 8730, Beijing 100080
Probing of the Isospin-Dependent Mean Field and Nucleon-Nucleon Cross Section in a Medium by Nucleon Emissions
LIU Jian-Ye1,2,3,4;XING Yong-Zhong1,2;GUO Wen-Jun3
1Institute for Theory of Modern Physics, Tianshui Normal University, Tianshui 741000
2Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000
3Institute of Modern Physics, Chinese Academy of Sciences, PO Box 31, Lanzhou 730000
4CCAST (Word Laboratory), PO Box 8730, Beijing 100080
Abstract： We study the isospin effects of the mean field and two-body collision on the nucleon emissions at the intermediate energy heavy ion collisions by using an isospin-dependent transport theory. The calculated results show that the nucleon emission number Nn depends sensitively on the isospin effect of nucleon nucleon cross section and weakly on the isospin-dependent mean field for neutron-poor system in higher beam energy region. In particular, the correlation between the medium correction of two-body collision and the momentum-dependent interaction enhances the dependence of nucleon emission number Nn on the isospin effect of nucleon nucleon cross section. On the contrary, the ratio of the neutron proton ratio of the gas phase to the neutron proton ratio of the liquid phase, i.e., the degree of isospin fractionation <(N/Z)gasb/<(N/Z)liq>b depends sensitively on the isospin-dependent mean field and weakly on the isospin effect of two-body collision for neutron-rich system in the lower beam energy region. In this case, Nn and <(N/Z)gasb/<(N/Z)liq>b are the probes for extracting the information about the isospin-dependent nucleon nucleon cross section in the medium and the isospin-dependent mean field, respectively.
LIU Jian-Ye;;XING Yong-Zhong;GUO Wen-Jun. Probing of the Isospin-Dependent Mean Field and Nucleon-Nucleon Cross Section in a Medium by Nucleon Emissions[J]. 中国物理快报, 2003, 20(5): 643-646.
LIU Jian-Ye, , XING Yong-Zhong, GUO Wen-Jun. Probing of the Isospin-Dependent Mean Field and Nucleon-Nucleon Cross Section in a Medium by Nucleon Emissions. Chin. Phys. Lett., 2003, 20(5): 643-646.
2003, Vol. 20 
