Constraints on the Galactic Dark Matter signal from the Fermi-LAT measurement of the diffuse gamma-ray emission

TL;DR

This study uses Fermi-LAT gamma-ray data to set constraints on dark matter properties by analyzing diffuse emission, challenging some dark matter interpretations of cosmic ray anomalies and refining the viable mass range.

Contribution

It provides new constraints on dark matter annihilation or decay signals using gamma-ray data, accounting for astrophysical uncertainties and improving limits on dark matter models.

Findings

No robust dark matter signal detected.

Constraints challenge dark matter explanations for cosmic ray anomalies.

Limits impact the viable mass range for thermal dark matter production.

Abstract

We study diffuse gamma-ray emission at intermediate Galactic latitudes measured by the Fermi Large Area Telescope with the aim of searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We set both, conservative dark matter limits requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission and limits derived based on modeling the foreground astrophysical diffuse emission. Uncertainties in several parameters which characterize conventional astrophysical emission are taken into account using a profile likelihood formalism. The resulting limits impact the range of particle masses over which dark matter thermal production in the early Universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as annihilation of dark matter.