Z′ model for b →s flavor anomalies Z′ MODEL for b →s ... CHENG-WEI CHIANG, XIAO-GANG HE, and GERMAN VALENCIA
Journal
Physical Review D - Particles, Fields, Gravitation and Cosmology
Journal Volume
93
Journal Issue
7
Date Issued
2016
Author(s)
Abstract
We study the implications of flavor-changing neutral currents (FCNC's) in a model with the SU(2)l×SU(2)h×U(1)Y electroweak gauge symmetry for several anomalies appearing in b→s induced B decays in LHCb data. In this model, SU(2)l and SU(2)h govern the left-handed fermions in the first two generations and the third generation, respectively. The physical Z and Z′ generate the b→s transition at tree level, leading to additional contributions to the b→s semileptonic operators O9,10. We find that although Bs-Bs mixing constrains the parameters severely, the model can produce values of C9,10NP in the range determined by Descotes-Genon et al. (Global analysis of b→s anomalies, arXiv:1510.04239) for this scenario to improve the global fit of observables in decays induced by the b→sμμ transition. The Z′ boson in this model also generates tree-level FCNC's for the leptonic interactions that can accommodate the experimental central value of RK=B(B→Kμμ)/B(B→Keē)=0.75. In this case, the model predicts sizable branching ratios for B→Keτ, B→Kτē, and an enhancement of B→Kττ with respect to its standard model value.
Type
journal article