Constraining Dark Matter Properties with Gamma-Rays from the Galactic Center with Fermi-LAT

We study the capabilities of the Fermi satellite to constrain particle dark matter properties, as annihilation cross section, mass and branching ratio into dominant annihilation channels. Besides the prompt gamma-ray flux, we also take into account the contribution from the electrons/positrons produced in dark matter annihilations to the gamma-ray signal via inverse Compton scattering off the interstellar photon background, which turns out to be crucial in the case of dark matter annihilations into mu+mu- and e+e- pairs. We study the signal dependence on different parameters like the region of observation, the density profile, the inclusion of systematic uncertainties in the gamma-ray background, the assumptions for the dark matter model and the uncertainties in the propagation model. If Fermi is able to distinguish a possible dark matter signal from the large gamma-ray background, we show that for dark matter masses below ~200 GeV, the Fermi experiment will likely be able to determine dark matter properties with good accuracy.