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arXiv 0909.4931hep-lat
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从畴壁费米子看QCD中的S参数

The S Parameter in QCD from Domain Wall Fermions

Peter A. Boyle, Luigi Del Debbio, Jan Wennekers, James M. Zanotti

摘要:

本文用格点量子色动力学方法在a-1 = 2.33GeV的尺度上对n_f = 2 + 1型畴壁费米子进行了模拟,计算了SU(2)低能常数l_5和带电π介子与中性π介子之间的质量分裂。将l5与QCD中的S参数联系起来,我们得到S(mH= 120 GeV)= 0.42(7),与以前的测定结果一致。我们的结果可以与来自电弱精确数据的S值进行比较,这些数据限制了像Technicolor这样的新物理的强相互作用模型。本文的工作是对标准模型以外的畴壁费米子理论计算S参数方法的一个检验。我们还推断出一个与实验一致的介子质量分裂值。

英文摘要:

We have computed the SU(2) Low Energy Constant l5 and the mass splitting between charged and neutral pions from a lattice QCD simulation of nf = 2 + 1 flavors of Domain Wall Fermions at a scale of a-1 = 2.33GeV. Relating l5 to the S parameter in QCD we obtain a value of S(mH=120GeV) = 0.42(7), in agreement with previous determinations. Our result can be compared with the value of S from electroweak precision data which constrains strongly interacting models of new physics like Technicolor. This work in QCD serves as a test for the methods to compute the S parameter with Domain Wall Fermions in theories beyond the Standard Model. We also infer a value for the pion mass splitting in agreement with experiment.

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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