Fermi-LAT constraints on diffuse Dark Matter annihilation from the Galactic Halo

TL;DR

This paper uses Fermi-LAT gamma-ray data and a systematic background model variation to set upper limits on dark matter annihilation cross-section in the Galactic Halo.

Contribution

It introduces a profile likelihood analysis incorporating background uncertainties to constrain dark matter properties.

Findings

Preliminary upper limits on dark matter annihilation cross-section.

Systematic variation of background models impacts the limits.

Constraints depend on the galactic diffuse background modeling.

Abstract

Our Galaxy resides in the center of a vast "Halo" of Dark Matter (DM). This concentration produces, in many viable particle physics models, an indirect Weakly Interacting Massive Particle (WIMP) annihilation signal that peaks in the Fermi-LAT's energy range. Our knowledge of the diffuse background is essential to placing reasonable limits on the DM mass and cross-section. We incorporate a systematic variation of the GALPROP galactic diffuse background model, constrained by current cosmic-ray measurements, into a profile likelihood analysis and present preliminary upper limits on the DM annihilation cross-section using the Fermi-LAT data.