2024/12/26 by Chih-Ting Lu, Lu, Chih-Ting, Xiao-Yi Luo +3 · 1 citation
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Atomic and Subatomic Physics Research #Quantum and Classical Electrodynamics
paper · pdf · doi:10.48550/arxiv.2412.19292
We conduct a comprehensive analysis of potential annihilation processes of light dark matter (DM) in minimal Higgs portal models near supermassive black hole (Sgr A⋆) in the Galactic Center, considering interactions between DM particles mediated by either a light scalar or pseudoscalar with couplings cs and cp . Accelerated by the supermassive black hole, DM particles can reach velocities up to half the speed of light, significantly enhancing the p -wave annihilation cross-section, allowing forbidden annihilation channels within specific mass ranges, and producing unique gamma-ray spectral signals. Utilizing gamma-ray observation from Fermi Large Area Telescope (Fermi-LAT) in the direction of Sgr A⋆, we constrain light DM parameter in the mass range of 0.3-10 GeV . Our results indicate that the couplings cs and cp are constrained to the order of 10-5 , corresponding to a DM annihilation cross-section as low as 10-38 \rm cm3/\rm s. In the future, the Very Large Gamma-ray Space Telescope (VLAST), with a larger detection area and broader detection range from 1 MeV to 1 TeV, will enhance our ability to probe sub-GeV DM and offer the opportunity to further study the forbidden annihilation scenario.