Abstract:

The existence of tiny but non-zero neutrino masses is one possible hint toward new physics beyond the Standard Model. One interesting scenario is to generate such small neutrino masses at loop level. In this talk, I will discuss a particular scenario, in which Majorana neutrino masses are induced by a new high-dimensional effective lepton-number-violating operator. Such scenario naturally predicts the neutrino mass matrix to be in the form of normal ordering, and gives rise to the large rates of neutrinoless double beta decays. I then discuss a specific model realising this mechanism, paying attention to its connection to dark matter physics. We also consider the constraints from flavor physics and electroweak precision test in this model.