Visible and Dark Matter Genesis and Cosmic Positron/Electron Excesses

TL;DR

This paper proposes a model linking dark matter and baryonic matter densities with neutrino mass generation, explaining cosmic positron/electron excesses through dark matter decay into leptons.

Contribution

It introduces a Dirac seesaw model where dark matter relic density and baryon asymmetry are generated simultaneously, naturally explaining their observed coincidence.

Findings

Dark matter decays predominantly into leptons.

The model accounts for cosmic positron/electron excesses.

Dark matter and baryonic matter densities are connected through asymmetry generation.

Abstract

Dark and baryonic matter contribute comparable energy density to the present Universe. The dark matter may also be responsible for the cosmic positron/electron excesses. We connect these phenomena with Dirac seesaw for neutrino masses. In our model (i) the dark matter relic density is a dark matter asymmetry generated simultaneously with the baryon asymmetry so that we can naturally understand the coincidence between the dark and baryonic matter; (ii) the dark matter mostly decays into the leptons so that its decay can interpret the anomalous cosmic rays with positron/electron excesses.