Asymmetric Dark Matter from Leptogenesis

TL;DR

This paper introduces a novel model where asymmetric dark matter and lepton asymmetries are generated simultaneously via two-sector leptogenesis, accommodating a wide range of dark matter masses and offering new phenomenological possibilities.

Contribution

The model uniquely links dark matter, lepton asymmetry, and neutrino masses through two-sector leptogenesis, allowing for diverse dark matter masses and novel detection mechanisms.

Findings

Supports dark matter masses from keV to 10 TeV.

Proposes mechanisms for late-time dark matter decay and oscillations.

Highlights potential for indirect detection signals.

Abstract

We present a new realization of asymmetric dark matter in which the dark matter and lepton asymmetries are generated simultaneously through two-sector leptogenesis. The right-handed neutrinos couple both to the Standard Model and to a hidden sector where the dark matter resides. This framework explains the lepton asymmetry, dark matter abundance and neutrino masses all at once. In contrast to previous realizations of asymmetric dark matter, the model allows for a wide range of dark matter masses, from keV to 10 TeV. In particular, very light dark matter can be accommodated without violating experimental constraints. We discuss several variants of our model that highlight interesting phenomenological possibilities. In one, late decays repopulate the symmetric dark matter component, providing a new mechanism for generating a large annihilation rate at the present epoch and allowing for mixed warm/cold dark matter. In a second scenario, dark matter mixes with the active neutrinos, thus presenting a distinct method to populate sterile neutrino dark matter through leptogenesis. At late times, oscillations and dark matter decays lead to interesting indirect detection signals.