Anders E. Thomsen (U Bern)
The Standard Model (SM) is augmented with a U(1)B−3Lμ gauge symmetry spontaneously brokenabove the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks S1(3)= (3,1(3),1/3) charged under U(1)B−3Lμ mediate the intriguing effects observed in muon (g−2), RK(∗) and b→sμ+μ−, while generically evading all other phenomenological constraints. The fermionic sectoris minimally extended with three right-handed neutrinos, and a successful type-I seesaw mechanismis realized. Charged lepton flavor violation and proton decay—common predictions of leptoquarks—are postponed to the dimension-6 effective Lagrangian. Unavoidable radiative corrections in theHiggs mass and muon Yukawa favor leptoquark masses interesting for collider searches. The parameters of the model are radiatively stable and can be evolved by the renormalization group to the Planck scale without inconsistencies. Alternative models based on a U(1)Lμ−Lτ gauge symmetryare proposed for comparison.
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