标题： 核平均场模型的配对间隙 显示英文标题

标题： Pairing gaps from nuclear mean-field models

摘要： 我们讨论了球形半幻数核链中的配对间隙（作为原子核配对关联的一种度量），这些研究是在自洽的核平均场模型框架下进行的。 传统的BCS模型和近似的投影先于变分的Lipkin-Nogami方法的方程被表述为有效相互作用的局域密度泛函。 我们计算了平均场能量和配对能量的Lipkin-Nogami修正值。 配对间隙的各种定义被讨论，包括三点、四点和五点质量差公式、配对势的平均矩阵元以及单准粒子能量。 实验得到的配对间隙值与采用BCS和Lipkin-Nogami模型中δ配对力以及密度依赖的δ相互作用的计算结果进行了比较。 奇数核使用球形阻塞近似法进行计算，该方法忽略了奇数核中部分芯子极化效应。 我们发现五点质量差公式对奇偶交错给出了非常稳健的描述，对于某些核，其他间隙近似值可能相差高达30%。 显示英文摘要

摘要： We discuss the pairing gap, a measure for nuclear pairing correlations, in chains of spherical, semi-magic nuclei in the framework of self-consistent nuclear mean-field models. The equations for the conventional BCS model and the approximate projection-before-variation Lipkin-Nogami method are formulated in terms of local density functionals for the effective interaction. We calculate the Lipkin-Nogami corrections of both the mean-field energy and the pairing energy. Various definitions of the pairing gap are discussed as three-point, four-point and five-point mass-difference formulae, averaged matrix elements of the pairing potential, and single-quasiparticle energies. Experimental values for the pairing gap are compared with calculations employing both a delta pairing force and a density-dependent delta interaction in the BCS and Lipkin-Nogami model. Odd-mass nuclei are calculated in the spherical blocking approximation which neglects part of the the core polarization in the odd nucleus. We find that the five-point mass difference formula gives a very robust description of the odd-even staggering, other approximations for the gap may differ from that up to 30% for certain nuclei.