Radiative Seesaw Model with Degenerate Majorana Dark Matter

TL;DR

This paper presents a three-loop neutrino mass model featuring a degenerate Majorana dark matter candidate, predicting observable gamma-ray signals for indirect detection experiments.

Contribution

It introduces a novel three-loop induced neutrino mass model with degenerate Majorana dark matter and explores its implications for lepton flavor violation and indirect detection.

Findings

Degenerate Majorana dark matter achieved at two-loop level

Mass splitting >200 keV to satisfy direct detection constraints

Prediction of monochromatic photon excess detectable by INTEGRAL

Abstract

We study a three loop induced neutrino mass model with exotic vector-like isospin doublet leptons which contain a dark matter candidate. Then we explore lepton flavor violations, and dark matter physics in co-annihilation system. In this paper the nearly degenerate Majorana fermion dark matter can naturally be achieved at the two loop level, while the mass splitting can be larger than ${\cal O}$(200) keV which is required from the constraint of the direct detection search with spin independent inelastic scattering through $Z$ boson portal. As a result a monochromatic photon excess, its threshold energy is greater than ${\cal O}$(200) keV, is predicted in our model that could be measured through indirect detection experiments such as INTEGRAL.