A class of Z' models with non-universal couplings and protected flavor-changing interactions

Abstract

Motivated by the $b\to s\ell^+\ell^-$ anomalies recently reported by the LHCb collaboration, I present a class of flavored U(1)' gauge extensions of the Standard Model that naturally accommodates them and possesses a rich phenomenology. This model is characterized by the presence of tree-level flavor-changing interactions in the down-quark sector, protected by off-diagonal quark-mixing matrix elements. Anomaly cancellation fixes the extension of the symmetry to the lepton sector in a very specific way, giving rise to flavor-conserving family-non-universal Z' couplings. The fermion content of this model is the same as in the SM while the scalar sector is extended with an extra Higgs doublet and a scalar singlet. The model will be tested in the next run of LHC and presents specific correlations in certain flavor observables that allow to clearly discriminate among them and from other new physics signals.