标题： 核力介子交换理论中的离壳配对关联 显示英文标题

标题： Off-shell pairing correlations from meson-exchange theory of nuclear forces

摘要： 我们开发了一个关于核系统中非壳层配对关联的模型，该模型基于介子交换的核相互作用图像。 模型中的时间延迟是由Fock交换图产生的。 重子的复数能隙方程的核与介子的介质谱函数有关，该谱函数在随机相位近似中非微扰地进行评估。 该模型通过将相互作用分为长程的单π介子交换部分和短程部分（用Landau费米液体参数来参数化），应用于中子星外壳中的低密度中子物质。 得到的Eliashberg型耦合非线性积分方程通过迭代过程求解。我们发现自能扩展到几十分之一MeV量级的非壳层能量。 在低能下，由于与π介子模式耦合导致的中子对关联的阻尼较小，但随着能量增加，阻尼变得越来越重要。 我们讨论了一种改进的准经典近似，在此近似下获得了数值解。 显示英文摘要

摘要： We develop a model of off-mass-shell pairing correlations in nuclear systems, which is based on the meson-exchange picture of nuclear interactions. The temporal retardations in the model are generated by the Fock-exchange diagrams. The kernel of the complex gap equation for baryons is related to the in-medium spectral function of mesons, which is evaluated nonperturbatively in the random phase approximation. The model is applied to the low-density neutron matter in neutron star crusts by separating the interaction into a long-range one-pion-exchange component and a short-range component parametrized in terms of Landau Fermi liquid parameters. The resulting Eliashberg-type coupled nonlinear integral equations are solved by an iterative procedure.We find that the self-energies extend to off-shell energies of the order of several tens of MeV. At low energies the damping of the neutron pair correlations due to the coupling to the pionic modes is small, but becomes increasingly important as the energy is increased. We discuss an improved quasiclassical approximation under which the numerical solutions are obtained.