Indirect Searches for Secluded Dark Matter

Abstract

Dark matter remains one of the most important open problems in particle physics and cosmology. Weakly interacting massive particles (WIMPs) appear as an appealing solution, providing the right relic density with a cross-section at the electroweak scale, however, no WIMP signals were observed until now. Secluded models are good alternatives to the standard ones. In this case, instead of a direct annihilation to the standard model (SM) particles, the dark matter annihilates into mediators which subsequently decay into SM particles. In this way, we can avoid the stringent limits from direct searches, and, at the same time, secluded models can be probed by indirect detection experiments. Motivated by the appearance of secluded dark matter in several model building endeavors, in this talk, we will present the sensitivity of several gamma-ray instruments (current and prospects), including Fermi-LAT, H.E.S.S., CTA, and SWGO, to secluded dark matter annihilations in the inner galactic halo, and in the dwarf spheroidal galaxies, covering a wide range of possible DM masses, from tens of GeV to hundreds of TeV.

News on Dark Matter from ICRC 2021

“…Bounds on secluded DM have been computed in [32] as well, for a variety of final states from the mediators decays. Future sensitivities for the CTA and SWGO experiments are presented.…”

Constraining gamma-ray lines from dark matter annihilation using Fermi-LAT and H.E.S.S. data

“…As it is often assumed that dark matter particles interacted with SM particles in the early universe, it is reasonable to assume that such interactions might still take place today, especially in astrophysical regions which are dark matter dominated such as dwarf spheroidal galaxies. In this aspect, dark matter annihilations into SM particles will yield a continuous gamma-ray emission, which is not easily distinguished from other astrophysical emissions [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Nevertheless, dark matter annihilation into photon pairs produces monochromatic photons, which represent a smoking-gun signature of dark matter annihilation due to a relative lack of confounding astrophysical backgrounds.…”