Addressing the LHC flavor anomalies with horizontal gauge symmetries

We study the impact of an additional U(1)^' gauge symmetry with flavor-dependent charges for quarks and leptons on the LHC flavor anomalies observed in B→K*μ⁺μ^-, R(K)=B→Kμ⁺μ^-/B→Ke⁺e^-, and h→μτ. In its minimal version with two scalar doublets, the resulting model naturally explains the deviations from the Standard Model observed in B→K*μ⁺μ^- and $R(K)$. The CMS access in h→μτ can be explained by introducing a third scalar doublet, which gives rise to a prediction for τ→3μ. We investigate constraints from flavor observables and direct LHC searches for pp→Z^'→μ⁺μ^-. Our model successfully generates the measured fermion-mixing matrices and does not require vectorlike fermions, unlike previous attempts to explain these anomalies.