Influence of in-medium NN cross sections, symmetry potential, and impact parameter on isospin observables
Influence of in-medium NN cross sections, symmetry potential, and impact parameter on isospin observables
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介质中神经网络横截面、对称势和冲击参数对同位旋可观测量的影响
DOI：
10.1103/physrevc.85.024602
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发表时间：
2010-09
影响因子：
3.1
通讯作者：
Hang Liu
中科院分区：
文献类型：
--
作者：
Yingxun Zhang;D. D. S. Coupl;P. Danielewicz;Zhuxia Li;Hang Liu
我们探讨了中等内核核子横截面的影响，对称势和影响参数对IMQMD05代码中的中等能量重型离子碰撞中的同胞敏感可观察物，这是一种修改的量子分子动力学版本
We explore the influence of in-medium nucleon-nucleon cross section, symmetry potential and impact parameter on isospin sensitive observables in intermediate-energy heavy-ion collisions with the ImQMD05 code, a modified version of Quantum Molecular Dynamics model. At incident velocities above the Fermi velocity, we find that the density dependence of symmetry potential plays a more important role on the double neutron to proton ratio $DR(n/p)$ and the isospin transport ratio $R_i$ than the in-medium nucleon-nucleon cross sections, provided that the latter are constrained to a fixed total NN collision rate. We also explore both $DR(n/p)$ and $R_i$ as a function of the impact parameter. Since the copious production of intermediate mass fragments is a distinguishing feature of intermediate-energy heavy-ion collisions, we examine the isospin transport ratios constructed from different groups of fragments. We find that the values of the isospin transport ratios for projectile rapidity fragments with $Z\ge20$ are greater than those constructed from the entire projectile rapidity source. We believe experimental investigations of this phenomenon can be performed. These may provide significant tests of fragmentation time scales predicted by ImQMD calculations.