1305.5597 (Fermi-LAT Collaboration)
Fermi-LAT Collaboration
Weakly Interacting Massive Particles (WIMPs) are a theoretical class of particles that are excellent dark matter candidates. WIMP annihilation or decay may produce essentially monochromatic gamma rays detectable by the Fermi Large Area Telescope (LAT) against the astrophysical gamma-ray emission of the Galaxy. We have searched for spectral lines in the energy range 5--300 GeV using 3.7 years of data, reprocessed with updated instrument calibrations and an improved energy dispersion model compared to the previous \Fermi-LAT Collaboration line searches. We searched in five regions selected to optimize sensitivity to different theoretically-motivated dark matter density distributions. We did not find any globally significant lines in our a priori search regions and present 95% confidence limits for WIMP annihilation cross sections and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3\sigma, which translates to a global significance of 1.6\sigma. We discuss potential systematic effects in this search and why the significance of the line-like feature near 130 GeV is less than reported in other works.
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http://arxiv.org/abs/1305.5597
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