Search for gamma-ray spectral lines with the Fermi Large Area Telescope and dark matter implications

Abstract

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 annihilation cross sections of self-conjugate WIMPs and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3 standard deviations, which translates to a global significance of 1.5 standard deviations. We discuss potential systematic effects in this search, and examine the feature at 133 GeV in detail. We find that the use both of reprocessed data and of additional


Tutti gli autori

  • LOPARCO F.;GIORDANO F.;SPINELLI P.;FUSCO P.;RAINO' S.

Titolo volume/Rivista

Non Disponibile


Anno di pubblicazione

2013

ISSN

1550-7998

ISBN

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Numero di citazioni Wos

141

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Numero di citazioni Scopus

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Settori ERC

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