Dark Matter-Driven Low-Scale Leptogenesis via Neutrino Portal

TL;DR

This paper introduces a new low-scale leptogenesis model linking dark matter and matter-antimatter asymmetry, featuring novel CP violation sources and potential LHC signatures.

Contribution

It presents a unique framework connecting dark sector physics with leptogenesis through interference effects, expanding the mechanisms for CP asymmetry generation.

Findings

Enhanced CP violation from dark sector interference effects

Predictions of new dark-sector particles accessible at the LHC

Unified explanation for matter-antimatter asymmetry and dark matter abundance

Abstract

We propose a novel framework for low-scale leptogenesis within an extension of the Standard Model (SM) that includes three SU(2) singlet right-handed neutrinos, a singlet charged neutral fermion, and a real scalar field. In this setup, the CP asymmetry arises through a rich interplay of mechanisms, including two-body decays of the lightest right-handed neutrino into leptons and Higgs or into dark-sector particles, as well as multiple 2 -> 2 scattering processes involving visible and dark states. Crucially, the CP-violating phases originate not only from conventional vertex and self-energy corrections but also from novel interference effects mediated by the dark sector, which significantly enrich the sources of asymmetry. A distinctive feature of our model is the direct connection between the dark sector and leptogenesis, providing a unified explanation for both the matter-antimatter asymmetry and DM abundance. This connection leads to enhanced CP violation in neutrino interactions and predicts new dark-sector particles accessible at the LHC.