Constraints on dark matter with future MeV gamma-ray telescopes

TL;DR

Future MeV gamma-ray telescopes could significantly improve constraints on dark matter decay or annihilation, filling the sensitivity gap in the MeV energy range and advancing our understanding of dark matter properties.

Contribution

This work forecasts the sensitivity of upcoming gamma-ray observatories to dark matter signals, comparing potential bounds with existing constraints.

Findings

Projected sensitivities surpass current bounds in the MeV range

Potential to detect or constrain various dark matter decay and annihilation channels

Fills the sensitivity gap in the MeV gamma-ray energy band

Abstract

A number of new balloon or space-based $\gamma$-ray observatories have been proposed to close a "MeV gap" in sensitivity to $\gamma$ rays in the MeV-GeV energy band. One aspect of the science case for these instruments is their ability to constrain or discover decaying or annihilating dark matter. In this work, we forecast the sensitivity of these instruments for dark matter annihilation or decay for a range of possible Standard Model final states and compare to existing bounds.