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arXiv 0901.4688hep-ph
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pi0寿命的手性展开

Chiral expansions of the pi0 lifetime

Karol Kampf, Bachir Moussallam

摘要:

重新考察了轻夸克质量对$π^0$寿命的代数结果的修正。我们考虑NNLO校正,我们计算所有的一个循环和两个循环图,这有助于在NNLO的衰减振幅在两味手征展开。我们证明了当满足Weinberg相容性条件时,结果是可重正化的.我们发现,手征性异构体是目前在这个顺序不同的情况下,在非线性光学。这一结果可与格点量子色动力学模拟结合使用,后者的可行性最近已得到证实。讨论了单圈反常扇形中二味手征展开式与三味手征展开式之间的匹配,导出了耦合常数之间的关系。提出了一种改进的手征计数方法,将$m_s$计数为$O(p)$ .我们更新了所需的各种输入,并使用它来做出现象学预测。

英文摘要:

The corrections induced by light quark masses to the current algebra result for the $π^0$ lifetime are reexamined. We consider NNLO corrections and we compute all the one-loop and the two-loop diagrams which contribute to the decay amplitude at NNLO in the two-flavour chiral expansion. We show that the result is renormalizable, as Weinberg consistency conditions are satisfied. We find that chiral logarithms are present at this order unlike the case at NLO. The result could be used in conjunction with lattice QCD simulations, the feasibility of which was recently demonstrated. We discuss the matching between the two-flavour and the three-flavour chiral expansions in the anomalous sector at order one-loop and derive the relations between the coupling constants. A modified chiral counting is proposed, in which $m_s$ counts as $O(p)$. We have updated the various inputs needed and used this to make a phenomenological prediction.

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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