Leptonic Source of Dark Matter and Radiative Majorana or Dirac Neutrino Mass

TL;DR

This paper develops models where dark matter interacts with leptons through a softly broken U(1) lepton number, deriving neutrino mass models without extra symmetries and exploring specific discrete symmetries like Z_n.

Contribution

It introduces a unified framework for dark matter and neutrino mass models using softly broken U(1) lepton number, deriving models with discrete symmetries without additional assumptions.

Findings

Derived models with Z_n dark symmetry for Dirac neutrinos.

Showed that previous scotogenic models are special cases within this framework.

Provided explicit examples with Z_3 and Z_5 symmetries.

Abstract

The notion of U(1) lepton number (which may only be softly broken) is applied to models of dark matter which interacts with leptons. Previous scotogenic models of Majorana or Dirac neutrino mass are shown to be derivable in this framework without additional symmetries. Only complete renormalizable theories are considered. An explicit class of models with $Z_n$ ($n \geq 5$) lepton and dark symmetry for Dirac neutrinos is derived, as well as an example of $Z_3$ dark symmetry.