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arXiv · 1112.4171

Conservative upper limits on WIMP annihilation cross section from Fermi-LAT $γ$-rays

F. Donato·F. Calore·V. De Romeri
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Abstract

The spectrum of an isotropic extragalactic $γ$-ray background (EGB) has been measured by the Fermi-LAT telescope at high latitudes. Two new models for the EGB are derived from the subtraction of unresolved point sources and extragalactic diffuse processes, which could explain from 30% to 70% of the Fermi-LAT EGB. Within the hypothesis that the two residual EGBs are entirely due to the annihilation of dark matter (DM) particles in the Galactic halo, we obtain $conservative$ upper limits on their annihilation cross section \sigmav. Severe bounds on a possible Sommerfeld enhancement of the annihilation cross section are set as well. Finally, would {\sigmav} be inversely proportional to the WIMP velocity, very severe limits are derived for the velocity-independent part of the annihilation cross section.

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F. Donato, F. Calore, V. De Romeri. 2011-12-18. Conservative upper limits on WIMP annihilation cross section from Fermi-LAT $γ$-rays. https://doi.org/10.1088/1742-6596%2F375%2F1%2F012039

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