Third family quark–lepton unification at the TeV scale

Abstract We construct a model of quark–lepton unification at the TeV scale based on an S U ( 4 ) gauge symmetry, while still having acceptable neutrino masses and enough suppression in flavor changing neutral currents. An approximate U ( 2 ) flavor symmetry is an artifact of family-dependent gauge charges leading to a natural realization of the CKM mixing matrix. The model predicts sizeable violation of PMNS unitarity as well as a gauge vector leptoquark U 1 μ = ( 3 , 1 , 2 / 3 ) which can be produced at the LHC – both effects within the reach of future measurements. In addition, recently reported experimental anomalies in semi-leptonic B-meson decays, both in charged b → c τ ν and neutral b → s μ μ currents, can be accommodated.