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arXiv 1012.2163hep-phhep-exnucl-th
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手征夸克模型中的同位旋对称性破缺

Isospin Symmetry Breaking in the Chiral Quark Model

Huiying Song, Xinyu Zhang, Bo-Qiang Ma

摘要:

本文在手征夸克模型的框架下讨论了质子和中子之间价夸克和海夸克分布的同位旋对称性破缺。我们假设同位旋对称性破缺是由同位旋多重态之间的质量差引起的,然后分析了同位旋对称性破缺对Gottfried求和规则和NuTeV反常的影响。结果表明,尽管核子海中的味不对称性和质子与中子间的ISB都能导致Gottfried求和规则的违反,但在手征夸克模型的框架下,味不对称性是主要的贡献.我们还发现对NuTeV反常的修正是在相反的方向上,所以手征夸克模型中的同位旋对称性破缺不能消除NuTeV反常.值得注意的是,我们的结果ISB的价和海夸克分布是一致的马丁-罗伯茨-斯特林-索恩参数化的夸克分布。

英文摘要:

We discuss the isospin symmetry breaking (ISB) of the valence- and sea-quark distributions between the proton and the neutron in the framework of the chiral quark model. We assume that isospin symmetry breaking is the result of mass differences between isospin multiplets and then analyze the effects of isospin symmetry breaking on the Gottfried sum rule and the NuTeV anomaly. We show that, although both flavor asymmetry in the nucleon sea and the ISB between the proton and the neutron can lead to the violation of the Gottfried sum rule, the main contribution is from the flavor asymmetry in the framework of the chiral quark model. We also find that the correction to the NuTeV anomaly is in an opposite direction, so the NuTeV anomaly cannot be removed by isospin symmetry breaking in the chiral quark model. It is remarkable that our results of ISB for both valence- and sea-quark distributions are consistent with the Martin-Roberts-Stirling-Thorne parametrization of quark distributions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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