Diffuse gamma ray constraints on annihilating or decaying Dark Matter after Fermi

TL;DR

This paper uses Fermi gamma ray data to constrain dark matter models, excluding large parameter regions and refining interpretations of cosmic ray anomalies, especially favoring mu+mu- channels with cored profiles.

Contribution

It provides new constraints on dark matter annihilation and decay parameters using gamma ray observations, improving understanding of possible dark matter explanations for cosmic ray anomalies.

Findings

Large regions of dark matter parameter space are excluded.

Only mu+mu- channels with cored profiles fit the lepton data.

Constraints are derived for a wide range of dark matter masses and profiles.

Abstract

We consider the diffuse gamma ray data from FERMI first year observations and compare them to the gamma ray fluxes predicted by Dark Matter annihilation or decay (both from prompt emission and from Inverse Compton Scattering), for different observation regions of the sky and a range of Dark Matter masses, annihilation/decay channels and Dark Matter galactic profiles. We find that the data exclude large regions of the Dark Matter parameter space not constrained otherwise and discuss possible directions for future improvements. Also, we further constrain Dark Matter interpretations of the e+e- PAMELA/FERMI spectral anomalies, both for the annihilating and the decaying Dark Matter case: under very conservative assumptions, only models producing dominantly mu+mu- and assuming a cored Dark Matter galactic profile can fit the lepton data with masses around 2 TeV.