2023/12/08 by Luque, Pedro De la Torre, Balaji, Shyam, Silk, Joseph · 6 citations
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2312.04907
We explore the 511~keV emission associated to sub-GeV dark matter (DM) particles that can produce electron-positron pairs and form positronium after thermalizing. We use ∼16~yr of SPI data from INTEGRAL to constrain DM properties, considering the full positron propagation and losses, and the free electron density drop away from the Galactic plane. We show that the predicted longitude and latitude profiles vary significantly for different DM masses, unlike previous assumptions, and obtain the strongest limits on sub-GeV DM (from the MeV to a few GeV) so far, excluding cross-sections down to ⟨ σv ⟩ \lesssim10-32 cm3 s-1 for mχ∼1 MeV and ⟨ σv ⟩ \lesssim10-26 cm3 s-1 for mχ∼5 GeV and lifetimes up to τ\gtrsim 1029 \textrms (mχ∼1 MeV) and τ\gtrsim 1027 \textrms (mχ∼5~GeV) for the typical Navarro-Frenk-White DM profile. Our derived limits are robust within a factor of a few due to systematic uncertainties.