Anomaly-free local horizontal symmetry and anomaly-full rare B-decays

Abstract

The largest global symmetry that can be made local in the Standard Model + 3$ν_R$ while being compatible with Pati-Salam unification is $SU(3)_H\times U(1)_{B-L}$. The gauge bosons of this theory would induce flavour effects involving both quarks and leptons, and are a potential candidate to explain the recent reports of lepton universality violation in rare B meson decays. In this letter we characterise this type of models and show how they can accommodate the data and naturally be within reach of direct searches.

7 pages, 2 figures; v2: version published in PRD