Speaker
Description
Detection of high-energy diffuse gamma-rays is one of the most important aspects of modern astrophysics. Recently Tibet AS$_\gamma$ collaboration [1] has detected galactic sub-PeV diffuse gamma-rays, which also happens to be the highest energy diffuse gamma-rays detected to date. In this work [2], we show that these high-energy diffuse gamma rays can be an excellent probe for detecting PeV-scale decaying dark matter (DM). If heavy DM particles decay to various Standard Model (SM) states, they can ultimately hadronize or decay to final state high-energy photons which can then contribute to the diffuse gamma-rays detected. The recent detection agrees well with prior theoretical astrophysical models of diffuse gamma-ray production. Thus, considering various SM final states, different DM density profiles and various astrophysical background models we put bounds on the properties of decaying DM. We find that this gives us the strongest constraints on decaying DM for DM masses between a few PeV to a few tens of PeV. In future, an improved understanding of the astrophysical backgrounds and many such high energy gamma-ray detections can either discover or severely constrain heavy decaying DM.
References:
[1] Tibet ASgamma collaboration, M. Amenomori et al., First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies, Phys. Rev. Lett. 126 (2021) 141101, [2104.05181].
[2] T. N. Maity, A. K. Saha, A. Dubey and R. Laha, Search for dark matter using sub-PeV γ-rays observed by Tibet ASγ, Phys. Rev. D 105 (2022) L041301, [2105.05680].
