Observable flavor violation from spontaneous lepton number breaking

Abstract

We propose a simple model of spontaneous lepton number violation with potentially large flavor violating decays, including the possibility that majoron emitting decays, such as $\mu \to eJ$, saturate the experimental bounds. In this model the majoron is a singlet-doublet admixture. It generates a type-I seesaw for neutrino masses and contains also a vector-like lepton. As a by-product, the model can explain the anomalous $(g-2{)}_{\mu }$ in parts of its parameter space, where one expects that the branching ratio of the Higgs to muons is changed with respect to Standard Model expectations. However, the explanation of the muon $g-2$ anomaly would lead to tension with recent astrophysical bounds on the majoron coupling to muons.

32 pages, 5 figures, 2 tables; v2: Improved phenomenological analysis, Matches published version

References in corpus (7)

• Evidence for Higgs boson decay to a pair of muons
• Lepton flavor violation in low-scale seesaw models: SUSY and non-SUSY contributions
• A search for two body muon decay signals
• Search for Majoron-emitting modes of double-beta decay of ${}^{136}$Xe with EXO-200
• Ultralight scalars in leptonic observables
• Flavor-changing Majoron interactions with leptons
• Structure Of Flavor Changing Goldstone Boson Interactions

Cited by in corpus (5)

• Reach and complementarity of $\mu \to e$ searches
• Search for Majoron at the COMET Experiment
• High-precision muon decay predictions for ALP searches
• Neutrino masses from new Weinberg-like operators: Phenomenology of TeV scalar multiplets
• Search for the charged lepton flavor violating decay $\psi (3686)\to e^{\pm }{\mu }^{\mp }$