Radiative generation of neutrino masses and its experimental signals

Abstract

Tiny neutrino masses can arise naturally via loop diagrams. After a brief review of the radiative mass generation mechanism, I present a new model wherein TeV scale leptoquark scalars induce neutrino masses via two–loop diagrams. This model predicts the neutrino oscillation parameter sin2 θ13 to be close to the current experimental limit. The leptoquarks are accessible to experiments at the LHC since their masses must lie below 1.5 TeV, and their decay branching ratios probe neutrino oscillation parameters. Rare lepton flavor violating processes mediated by leptoquarks have an interesting pattern: μ → eγ may be suppressed, while μ → 3e and μ − e conversion in nuclei are within reach of the next generation experiments. Muon g− 2 receives new positive contributions, which can resolve the discrepancy between theory and experiment. New CP violating contributions to Bs−Bs mixing via leptoquark box diagrams are in a range that can explain the recently reported dimuon anomaly by the DO collaboration.