Flavor anomalies meet flavor symmetry

We construct an extension of the Standard Model with a scalar leptoquark Q iota similar to (3,1, - 13) and the discrete flavor symmetry Gf _ D17 x Z17 to explain anomalies observed in charged-current semileptonic B meson decays and in the muon anomalous magnetic moment, together with the charged fermion masses and quark mixing. The symmetry Zdiag 17 , contained in Gf, remains preserved by the leptoquark couplings, at leading order, and efficiently suppresses couplings of the leptoquark to the first generation of quarks and/or electrons, thus avoiding many stringent experimental bounds. The strongest constraints on the parameter space are imposed by the radiative charged lepton flavor violating decays a -mu y and mu -ey. A detailed analytical and numerical study demonstrates the feasibility to simultaneously explain the data on the lepton flavor universality ratios R(D) and R(D*) and the muon anomalous magnetic moment, while passing the experimental bounds from all other considered flavor observables.

Automated summary

We propose an extension of the Standard Model by introducing a scalar leptoquark to explain anomalies in charged-current semileptonic B meson decays and the muon anomalous magnetic moment. This extension also accounts for charged fermion masses and quark mixing. By using a discrete flavor symmetry, the couplings between the leptoquark and the first generation of quarks and/or electrons are suppressed, thus avoiding experimental bounds. Our study demonstrates that it is feasible to simultaneously explain the data on lepton flavor universality ratios and the muon anomalous magnetic moment, while satisfying other flavor observables.