Towards the discovery of new physics with lepton-universality ratios of b -> sll decays
Towards the discovery of new physics with lepton-universality ratios of b -> sll decays
复制标题
朝着发现轻子普适性比率 b -> sll 衰变的新物理学方向
DOI：
10.1103/physrevd.96.093006
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发表时间：
2017
影响因子：
5
通讯作者：
Shi Rui-Xiang
中科院分区：
文献类型：
--
作者：
Geng Li-Sheng;Grinstein Benjamin;Jaeger Sebastian;Camalich Jorge Martin;Ren Xiu-Lei;Shi Rui-Xiang
在标准模型中可以非常准确地预测轻子普遍性作为跃迁速率比的测试。因此，LHCb 实验所报告的 μ 子与电子衰变率之比与预期的差距表明了轻子非通用新物理学的真正表现。在本文中，我们在有效场论的背景下分析这些测量结果。首先，我们讨论不同算子之间的相互作用，并提供标准模型和可以解释的新物理场景中的预测。我们还为感兴趣的箱中的这些可观测值提供了近似数值公式，作为相关威尔逊系数的函数。其次，我们对 和 进行频率主义拟合。标准模型不同意这些测量的重要性。我们发现非常适合具有运算符组合的场景，并且相对于该区域的标准模型有拉力。我们分析的一个重要结论是，轻子特异性的贡献对于理解数据很重要。在新物理学选择性地与 μ 子耦合的假设下，我们还通过保守的误差评估来呈现与其他数据的拟合，并对更一般的情况进行评论。最后，我们讨论新的轻子普遍性比率，如果新物理学是观察到的差异的根源，那么它应该有助于在不久的将来发现新物理学的统计意义。
Tests of lepton-universality as rate ratios intransitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of thedecay rates thus point to genuine manifestations of lepton nonuniversal new physics. In this paper, we analyze these measurements in the context of effective field theory. First, we discuss the interplay of the different operators inandand provide predictions forin the Standard Model and in new-physics scenarios that can explain. We also provide approximate numerical formulas for these observables in bins of interest as functions of the relevant Wilson coefficients. Secondly, we perform frequentist fits toand. The Standard Model disagrees with these measurements atsignificance. We find excellent fits in scenarios with combinations ofoperators, with pulls relative to the Standard Model in the region of. An important conclusion of our analysis is that a lepton-specific contribution tois important to understand the data. Under the hypothesis that new-physics couples selectively to the muons, we also present fits to otherdata with a conservative error assessment and comment on more general scenarios. Finally, we discuss new lepton universality ratios that, if new physics is the origin of the observed discrepancy, should contribute to the statistically significant discovery of new physics in the near future.