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arXiv 0708.3526hep-ph
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QCD真空磁化率的1/N_c修正

1/N_c corrections to the magnetic susceptibility of the QCD vacuum

Klaus Goeke, Hyun-Chul Kim, M. M. Musakhanov, Marat Siddikov

摘要:

本文在瞬子真空的基础上,研究了考虑$1/N_c$修正的QCD真空的磁化率。本文从瞬子液体模型出发,导出了在流夸克质量以及外部阿贝尔矢量场和张量场存在下的规范轻夸克配分函数。我们考虑了$1/N_c$介子环修正,它对上(和下)夸克的磁化率的贡献约为15%。我们还考虑了来自瞬子真空的夸克-夸克相互作用的张量项以及有限宽度效应,这两者都是$\mathcal{O}(1/N_c)$阶的。张量项和有限宽度的影响是可以忽略不计的小。上夸克的最终结果为:$χ< iψ^\dagger ψ>_0 \simeq 35-40 \mathrm{MeV}$与夸克凝聚$<iψ^\dagger ψ>_0$ .我们还讨论了磁化率的π质量依赖性,以给出一个定性的指导方针的手征外推的晶格数据。

英文摘要:

We investigate the magnetic susceptibility of the QCD vacuum with the $1/N_c$ corrections taken into account, based on the instanton vacuum. Starting from the instanton liquid model we derive the gauged light-quark partition function in the presence of the current quark mass as well as of external Abelian vector and tensor fields. We consider the $1/N_c$ meson-loop corrections which are shown to contribute to the magnetic susceptibility by around 15% for the up (and down) quarks. We also take into account the tensor terms of the quark-quark interaction from the instanton vacuum as well as the finite-width effects, both of which are of order $\mathcal{O}(1/N_c)$. The effects of the tensor terms and finite width turn out to be negligibly small. The final results for the up-quarks are given as: $χ< iψ^\dagger ψ>_0 \simeq 35-40 \mathrm{MeV}$ with the quark condensate $<iψ^\dagger ψ>_0$. We also discuss the pion mass dependence of the magnetic susceptibility in order to give a qualitative guideline for the chiral extrapolation of lattice data.

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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