Effective Field Theory Approach to b →s (′), B →k (∗)ν ν ¯ and B →d (∗)τν with Third Generation Couplings

Abstract

The LHCb Collaboration reported anomalies in B→K∗μ+μ-, Bs→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(∗)ν. In this Letter we reexamine these decays and their correlations to B→K(∗)νν¯ 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 Vcb). In these regions of parameter space, B→K(∗)τμ and Bs→τμ can be order 10-6. Possible UV completions are briefly discussed.