Asymmetries in Extended Dark Sectors: A Cogenesis Scenario

TL;DR

This paper explores how asymmetries in multi-component dark sectors influence dark matter relic abundance, proposing a model that also accounts for neutrino masses and baryon asymmetry, with potential neutrino signals.

Contribution

It introduces a multi-component cogenesis model demonstrating the impact of asymmetries on dark matter and links it to neutrino and baryon asymmetries.

Findings

Asymmetries can determine dark matter energy density even if particles are symmetric.

The model predicts a monochromatic neutrino line detectable by telescopes.

Multiple dark matter components can be explained within a unified asymmetry framework.

Abstract

The observed dark matter relic abundance may be explained by different mechanisms, such as thermal freeze-out/freeze-in, with one or more symmetric/asymmetric components. In this work we investigate the role played by asymmetries in determining the yield and nature of dark matter in non-minimal scenarios with more than one dark matter particle. In particular, we show that the energy density of a particle may come from an asymmetry, even if the particle is asymptotically symmetric by nature. To illustrate the different effects of asymmetries, we adopt a model with two dark matter components. We embed it in a multi-component cogenesis scenario that is also able to reproduce neutrino masses and the baryon asymmetry. In some cases, the model predicts an interesting monochromatic neutrino line that may be searched for at neutrino telescopes.