Constraint on scalar leptoquark from low-energy leptonic observables
Abstract
We consider the flavor structure of the S1 leptoquark model and derive conservative constraints on the elements of the left- and right-handed coupling matrices in a number of representative scenarios. We focus on the cases where the muon g -2 deviation is explained by real muon couplings to either the top-quark or to the charm-quark or to all up-type quarks. The most significant constraints arise from charged lepton flavor-violating decays of the muon and the τ lepton and from the μ - e conversion process. Kaon decays and perturbativity provide further constraints. We find strong constraints on almost all coupling matrix elements, implying a very hierarchical matrix structure, where individual entries must differ by at least four orders of magnitude. The FlexibleSUSY program was used with appropriate model files incorporating the parametrization of the couplings in the up-type mass diagonal basis. The expressions for the leptonic observables were generated and cross-checked with the help of the NPointFunctions extension of the FlexibleSUSY program.
- Publication:
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Physical Review D
- Pub Date:
- November 2023
- DOI:
- 10.1103/PhysRevD.108.095027
- arXiv:
- arXiv:2305.05016
- Bibcode:
- 2023PhRvD.108i5027K
- Keywords:
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- High Energy Physics - Phenomenology