Charged-lepton decays from soft flavour violation

Abstract

We consider a two-Higgs-doublet extension of the Standard Model, with three right-handed neutrino singlets and the seesaw mechanism, wherein all the Yukawa-coupling matrices are lepton flavour-diagonal and lepton flavour violation is soft, originating solely in the non-flavour-diagonal Majorana mass matrix of the right-handed neutrinos. We consider the limit $m_R\to \infty$ of this model, where $m_R$ is the seesaw scale. We demonstrate that there is a region in parameter space where the branching ratios of all five charged-lepton decays ${\ell }_1^{-}\to {\ell }_2^{-}{\ell }_3^{+}{\ell }_3^{-}$ are close to their experimental upper bounds, while the radiative decays ${\ell }_1^{-}\to {\ell }_2^{-}\gamma$ are invisible because their branching ratios are suppressed by $m_R^{-4}$. We also consider the anomalous magnetic moment of the muon and show that in our model the contributions from the extra scalars, both charged and neutral, can remove the discrepancy between its experimental and theoretical values.

18 pages, changes in the abstract, extensive rewritting of section 5, three figures and one reference added, version matches publication in PLB

References in corpus (15)

• Evidence for oscillation of atmospheric neutrinos
• Theory and phenomenology of two-Higgs-doublet models
• Measurement of the rate of nu_e + d --> p + p + e^- interactions produced by 8B solar neutrinos at the Sudbury Neutrino Observatory
• Reevaluation of the Hadronic Contributions to the Muon g-2 and to alpha(MZ)
• (g-2)_mu and alpha(M_Z^2) re-evaluated using new precise data
• Combined Analysis of all Three Phases of Solar Neutrino Data from the Sudbury Neutrino Observatory
• Phenomenology of Neutrino Oscillations
• A precision constraint on multi-Higgs-doublet models
• Global Analyses of Neutrino Oscillation Experiments
• Research Proposal for an Experiment to Search for the Decay μ -> eee
• MEG Upgrade Proposal
• Soft lepton-flavor violation in a multi-Higgs-doublet seesaw model
• Seesaw model with softly broken L_e - L_μ- L_τ
• A Call for New Physics : The Muon Anomalous Magnetic Moment and Lepton Flavor Violation
• Note on the classification of super-resolution in far-field microscopy and information theory

Cited by in corpus (3)

• Charged Lepton Flavor Violation in a class of Radiative Neutrino Mass Generation Models
• Radiative seesaw corrections and charged-lepton decays in a model with soft flavour violation
• About heavy neutrinos: Lepton-flavor violation in decays of charged leptons