Density and temperature dependence of nucleon-nucleon elastic cross section
Density and temperature dependence of nucleon-nucleon elastic cross section
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DOI：
10.1103/physrevc.69.017601
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发表时间：
2003-12
影响因子：
3.1
通讯作者：
Qingfeng Li;Zhu-xia Li;E. Zhao
中科院分区：
文献类型：
--
作者：
Qingfeng Li;Zhu-xia Li;E. Zhao
基于含δ [a(0)(980)]介子的密度依赖相对论强子理论的有效拉格朗日，研究了介质中中子-质子、质子-质子（中子-中子）弹性散射截面(sigma（np)*、sigma(pp(nn))*）。我们的研究表明，在低密度下，sigma(np)*大约是sigma(pp(nn))*的三到四倍，而在高于正常密度的密度下，同位旋效应几乎被消除。由于与δ介子的耦合，在质子和中子质量分裂后的同位旋不对称介质中，sigma(nn)*和sigma(pp)*是不同的。同位旋对介质中核子弹性截面密度依赖性的影响主要由等矢量δ介子和介子贡献。研究了温度对σ (np)*和σ (pp(nn))*的影响。结果表明，与密度效应相比，温度效应较弱，但随着密度的增大，温度效应变得明显。
The in-medium neutron-proton, proton-proton (neutron-neutron) elastic scattering cross sections (sigma(np)*,sigma(pp(nn))*) are studied based on the effective Lagrangian of density dependent relativistic hadron theory in which the delta[a(0)(980)] meson is included. Our study shows that at low densities the sigma(np)* is about three to four times larger than sigma(pp(nn))* and at densities higher than the normal density the isospin effect is almost washed out. Because of coupling to delta meson the sigma(nn)* and sigma(pp)* are different in isospin asymmetric medium following the splitting of the proton and neutron masses. The isospin effect on the density dependence of the in-medium nucleon elastic cross section is dominantly contributed by the isovector delta and rho mesons. The temperature effect on the sigma(np)* and sigma(pp(nn))* is studied. It is shown that the temperature effect is weaker compared with the density effect but it becomes obvious as density increases.