The Inverse Seesaw Family: Dirac And Majorana

TL;DR

This paper develops a general criterion for inverse seesaw neutrino models, introduces Dirac and generalized inverse seesaw mechanisms, and discusses their testability through collider experiments and lepton flavor violation.

Contribution

It provides a unifying criterion for inverse seesaw models, introduces Dirac inverse seesaw models, and explores multiple suppression mechanisms in these frameworks.

Findings

Established a criterion for classifying inverse seesaw models.

Derived the Dirac analogue of the inverse seesaw model.

Identified testable signatures in colliders and lepton flavor violation.

Abstract

After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking "$\mu$-terms". These models can be tested both in colliders and with the observation of lepton flavour violating processes.