A minimal flavored $U(1{)}^{\prime }$ for $B$-meson anomalies

Abstract

We consider an anomaly-free $U(1{)}^{\prime }$ model with favorable couplings to heavy flavors in the Standard Model(SM), as motivated by $B$-meson anomalies at LHCb. Taking the $U(1{)}^{\prime }$ charge to be $Q^{\prime }=y(L_{\mu }-L_{\tau })+x(B_3-L_3)$, we can explain the $B$-meson anomalies without invoking extra charged fermions or flavor violation beyond the SM. We show that there is a viable parameter space with a small $x$ that is compatible with other meson decays, tau lepton and neutrino experiments as well as the LHC dimuon searches. We briefly discuss the prospects of discovering the $Z^{\prime }$ gauge boson at the LHC in the proposed model.

Comments: 20 pages, 4 figures, v2: references and discussion on electroweak precision test added, v3: Version to appear in Physical Review D