标题： 中子-质子弹性散射截面的同位旋依赖性 显示英文标题

标题： Isospin Dependence of Nucleon-Nucleon Elastic Cross Section

摘要： 基于QHD-II型拉格朗日量，在微观输运理论的框架下研究了核介质中的中子-质子、质子-质子（中子-中子）散射截面（$\sigma_{np}^{*}$,$\sigma_{pp(nn)}^{*}$）。 结果表明，对于自由核子-核子散射截面，同位旋依赖性主要由$\rho$介子场引起。 核子-核子散射截面的介质修正也依赖于同位旋，$\sigma_{np}^{*}$对重子密度的依赖较弱，而$\sigma_{pp(nn)}^{*}$对重子密度有显著依赖，这是由于核子质量和$\rho$介子质量的介质修正对$\sigma_{np}$和$\sigma_{pp(nn)}$的影响不同所致。 显示英文摘要

摘要： The in-medium neutron-proton, proton-proton(neutron-neutron) scattering cross sections($\sigma_{np}^{*}$, $\sigma_{pp(nn)}^{*}$) are studied based on QHD-II type Lagrangian within the framework of the microscopic transport theory. The results demonstrate that, for free nucleon-nucleon scattering cross sections, the isospin dependence is dominantly caused by $\rho$ meson field. The medium correction of nucleon-nucleon scattering cross sections is also isospin dependent, $\sigma_{np}^{*}$ depends on the baryon density weakly and $\sigma_{pp(nn)}^{*}$ depends on the baryon density significantly, which is due to the different effects of the medium correction of nucleon mass and $\rho$ meson mass on $\sigma_{np}$ and $\sigma_{pp(nn)}$, respectively