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arXiv 1407.0926hep-phnucl-th
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手征展开和1/Nc展开的重子矢量流

The baryon vector current in the combined chiral and 1/Nc expansions

Ruben Flores-Mendieta, Jose L. Goity

摘要:

在大Nc重子手征微扰理论中,计算了单圈量级的重子矢量流,其中Nc是色数。系统地分析了八重态和十重态中间态的环图,并考虑了十重态-八重态质量差和SU(3)味对称性破缺的影响。由于QCD重子的大Nc自旋味对称性,在不同的单圈图之间存在大Nc相消。通过几次拟合将结果与现有的实验数据进行比较,以提取有关未知参数的信息。大Nc重子手征微扰理论的预言与1/Nc展开的预言和实验数据都符合得很好。SU(3)味对称性破缺的影响|德尔塔S| =1的矢量电流形状因子f1(0)导致相对于相应的SU(3)对称值减小百分之几。

英文摘要:

The baryon vector current is computed at one-loop order in large-Nc baryon chiral perturbation theory, where Nc is the number of colors. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis and the effects of the decuplet-octet mass difference and SU(3) flavor symmetry breaking are accounted for. There are large-Nc cancellations between different one-loop graphs as a consequence of the large-Nc spin-flavor symmetry of QCD baryons. The results are compared against the available experimental data through several fits in order to extract information about the unknown parameters. The large-Nc baryon chiral perturbation theory predictions are in very good agreement both with the expectations from the 1/Nc expansion and with the experimental data. The effect of SU(3) flavor symmetry breaking for the |Delta S|=1 vector current form factors f1(0) results in a reduction by a few percent with respect to the corresponding SU(3) symmetric values.

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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