A Model Independent Method to Study Dark Matter induced Leptons and Gamma rays

Abstract

By using recent data, we directly determine the dark matter (DM) induced $e^{\pm }$ spectrum at the source from experimental measurements at the earth, without reference to specific particle physics models. The DM induced gamma rays emitted via inverse Compton scattering are then obtained in a model independent way. However the results depend on the choice of the astrophysical $e^{\pm }$ background, which is not reliably known. Nevertheless, we calculate, as an illustration, the fluxes of gamma rays from the Fornax cluster in the decaying DM scenario with various astrophysical $e^{\pm }$ backgrounds. Without any assumptions on details of the DM model, the predictions turn out to be either in disagreement with or only marginally below the upper limits measured recently by the Fermi-LAT Collaboration. In addition, these DM induced ICS gamma rays in the GeV range are shown to be almost independent of choices of cosmic ray propagation model and of DM density profile, when a given astrophysical $e^{\pm }$ background is assumed. This provides a strong constraint on decaying DM scenario as the gamma rays may be produced in other processes besides inverse Compton scattering, such as the bremsstrahlung and neutral pion decays.

14 pages, 5 figures, Latex, to match the published version

References in corpus (9)

• Observation of an anomalous positron abundance in the cosmic radiation
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Fermi LAT observations of cosmic-ray electrons from 7 GeV to 1 TeV
• Constraints on cosmic-ray propagation models from a global Bayesian analysis
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Prospects of detecting gamma-ray emission from galaxy clusters: cosmic rays and dark matter annihilations
• Gamma-rays from Nearby Clusters: Constraints on Selected Decaying Dark Matter Models
• Decaying Dark Matter in Supersymmetric SU(5) Models
• Inverse Problem of Cosmic-Ray Electron/Positron from Dark Matter

Cited by in corpus (2)

• Indirect Searches for Decaying Dark Matter
• Gamma Ray Constraints on Flavor Violating Asymmetric Dark Matter