TeV Scale Neutrino Mass Generation, Minimal Inelastic Dark Matter, and High Scale Leptogenesis

TL;DR

This paper proposes a model extending the Standard Model that simultaneously achieves TeV-scale neutrino mass generation, inelastic dark matter, and high-scale leptogenesis, with testable predictions for experiments.

Contribution

It introduces a novel model with specific new particles and symmetries that unifies neutrino mass, dark matter, and leptogenesis at different energy scales.

Findings

Realizes testable TeV-scale type-II seesaw with two neutrino masses

Provides a minimal inelastic dark matter candidate from new fermions

Supports thermal or nonthermal leptogenesis via singlet scalar decays

Abstract

The seesaw and leptogenesis commonly depend on the masses of same particles, and thus are both realized at the same scale. In this work, we demonstrate a new possibility to realize a TeV-scale neutrino seesaw and a natural high-scale leptogenesis. We extend the standard model by two gauge-singlet scalars, a vector-like iso-doublet fermion and one iso-triplet Higgs scalar. Our model respects a softly broken lepton number and an exactly conserved $Z_2$ discrete symmetry. It can achieve three things altogether: (i) realizing a testable type-II seesaw at TeV scale with two nonzero neutrino mass-eigenvalues, (ii) providing a minimal inelastic dark matter from the new fermion doublets, and (iii) accommodating a thermal or nonthermal leptogenesis through the singlet scalar decays. We further analyze the current experimental constraints on our model and discuss the implications for the dark matter direct detections and the LHC searches.