2021/03/31 by Admir Greljo, Peter Stangl, Anders Eller Thomsen
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Electron #Gauge (firearms) #Higgs boson #Lepton #Leptoquark #Muon #Neutrino #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Scalar (mathematics) #Seesaw mechanism #Seesaw molecular geometry #Standard Model (mathematical formulation) #Yukawa potential #hep-ph
paper · pdf · doi:10.1016/j.physletb.2021.136554
11 pages, 4 figures. Version2: Updated after the g-2 release. Discussion on alternative models extended. References added
arxiv created 2021/04/08 · openalex publication_date 2021/07/28 · arxiv updated 2021/08/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Standard Model (SM) is augmented with a U(1)B−3Lμ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks S1(3)=(3‾,1(3),13) charged under U(1)B−3Lμ mediate the intriguing effects observed in muon (g−2), RK(⁎), and b→sμ+μ− angular distributions, while generically evading all other phenomenological constraints. The fermionic sector is minimally extended with three right-handed neutrinos, and a successful type-I seesaw mechanism is realized. Charged lepton flavor violation is effectively suppressed, and proton decay—a common prediction of leptoquarks—is postponed to the dimension-6 effective Lagrangian. Unavoidable radiative corrections in the Higgs 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 lepton-flavored gauge extensions of the SM, under which leptoquarks become muoquarks, are proposed for comparison.