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Title: Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~ 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. As a result, we quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe ofmore » DM particle signals.« less
  1. Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). et al.
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1475-7516; arXiv eprint number arXiv:1501.05464
Grant/Contract Number:
AC02-07CH11359; AC02-76SF00515
Accepted Manuscript
Journal Name:
Journal of Cosmology and Astroparticle Physics
Additional Journal Information:
Journal Volume: 2015; Journal Issue: 09; Journal ID: ISSN 1475-7516
Institute of Physics (IOP)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Fermi-LAT; Fermi LAT Collaboration
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; gamma ray experiments; dark matter experiments; dark matter theory; gamma ray theory; dark matter simulations