Search for dark matter signatures in the cosmic-ray electron and positron spectrum measured by the Fermi Large Area Telescope

Abstract

Over its ten years of mission the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events. Possible features in their energy spectrum could be a signature of the presence of nearby astrophysical sources or of more exotic sources, such as annihilating or decaying dark matter particles in the Galaxy. In addition, the capture and subsequent annihilation of dark matter particles in the Sun via long-lived dark mediators can yield high-energy electrons and positrons reaching the Earth, which are a probe for the dark matter-nucleon scattering cross section. We present the results of the search for possible features in the cosmic-ray electron and positron spectrum from our Galaxy and towards the Sun. We set constraints on the the velocity-averaged dark matter annihilation cross section and on the dark matter-nucleon scattering cross section up to dark matter masses of 1.7 TeV.