Radiative Neutrino Mass Generation through Vector-like Quarks

Abstract

A new model of radiative neutrino masses generated via two-loop diagrams is proposed involving a charge 2/3 vector-like quark and a doublet of leptoquark scalars. This model predicts one of the neutrinos to be massless and admits both the normal and inverted neutrino mass hierarchies with correlated predictions for l_i \rightarrow l_j + \gamma branching ratios. New contributions to CP violation in B_s-\bar{B}_s mixing arise in the model through leptoquark box diagrams, which can explain the anomalous dimuon events reported by the DO collaboration. These leptoquarks, with masses below 500 GeV, also provide a natural resolution to the apparent discrepancy in the measured values of the CP violation parameters \sin2\beta and \epsilon_K.