标题： 上下夸克质量差异在核多体系统中的效应 显示英文标题

标题： Up-Down Quark Mass Difference Effect in Nuclear Many-Body Systems

摘要： 由于上下夸克质量差异导致的电荷对称性破缺的核子-核子力在夸克团模型中进行了评估。 它被应用于壳模型计算，以研究同位旋多重态的等距质量位移以及1s0d壳核中的同位旋混合矩阵元。 我们发现夸克质量差异效应的贡献很大，并与实验结果一致。 这一贡献可能解释了Okamoto-Nolen-Schiffer异常，而不是最近预测的由于大非壳修正而减少的介子混合贡献。 显示英文摘要

摘要： A charge-symmetry-breaking nucleon-nucleon force due to the up-down quark mass difference is evaluated in the quark cluster model. It is applied to the shell-model calculation for the isovector mass shifts of isospin multiplets and the isospin-mixing matrix elements in 1s0d-shell nuclei. We find that the contribution of the quark mass difference effect is large and agrees with experiment. This contribution may explain the Okamoto-Nolen-Schiffer anomaly, alternatively to the meson-mixing contribution, which is recently predicted to be reduced by the large off-shell correction.