Calibbi Lorenzo, Crivellin Andreas, Ota Toshihiko
State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Service de Physique Théorique, Université Libre de Bruxelles, C.P. 225, B-1050 Brussels, Belgium.
Phys Rev Lett. 2015 Oct 30;115(18):181801. doi: 10.1103/PhysRevLett.115.181801. Epub 2015 Oct 27.
The LHCb Collaboration reported anomalies in B→K^{}μ^{+}μ^{-}, B_{s}→ϕμ^{+}μ^{-}, and R(K)=B→Kμ^{+}μ^{-}/B→Ke^{+}e^{-}. Furthermore, BABAR, BELLE, and LHCb Collaborations found hints for the violation of lepton-flavor universality violation in R(D^{()})=B→D^{()}τν/B→D^{()}ℓν. In this Letter we reexamine these decays and their correlations to B→K^{()}νν[over ¯] using gauge invariant dim-6 operators. For the numerical analysis we focus on scenarios in which new physics couples, in the interaction eigenbasis, to third generation quarks and lepton only. We conclude that such a setup can explain the b→sμ^{+}μ^{-} data simultaneously with R(D^{()}) for small mixing angles in the lepton sector (of the order of π/16) and very small mixing angles in the quark sector (smaller than V_{cb}). In these regions of parameter space, B→K^{(*)}τμ and B_{s}→τμ can be order 10^{-6}. Possible UV completions are briefly discussed.
大型强子对撞机底夸克实验合作组报告了在(B→K^{}μ^{+}μ^{-})、(B_{s}→ϕμ^{+}μ^{-})以及(R(K)=B→Kμ^{+}μ^{-}/B→Ke^{+}e^{-})中存在异常。此外，BABAR、BELLE和大型强子对撞机底夸克实验合作组在(R(D^{()})=B→D^{()}τν/B→D^{()}ℓν)中发现了轻子味普适性违反的迹象。在本信函中，我们使用规范不变的六维算符重新审视这些衰变及其与(B→K^{()}νν[\overline{]})的关联。对于数值分析，我们关注新物理在相互作用本征基下仅与第三代夸克和轻子耦合的情形。我们得出结论，对于轻子扇区中较小的混合角（约为(\pi/16)）以及夸克扇区中非常小的混合角（小于(V_{cb})），这样的设定可以同时解释(b→sμ^{+}μ^{-})数据与(R(D^{()}))。在这些参数空间区域中，(B→K^{(*)}τμ)和(B_{s}→τμ)可能为(10^{-6})量级。我们简要讨论了可能存在的紫外完备理论。
