Title: Pico-charged particles from dark matter decay explain 511 keV line and XENON1T signal
Speaker: Meshkat Rajaee (JBNU)
Abstract: There is a robust signal for a 511 keV photon line from the galactic center which may originate from dark matter particles with masses of a few MeV. Previously proposed dark matter scenarios are often challenged by the absence of corresponding signal from dwarf galaxies and/or by the absence of an impact on CMB through delayed recombination. I will explain how our proposed scenario can avoid these bounds. In our model dark matter first decays into a pair of intermediate pico-charged particles CC¯ with a lifetime much larger than the age of the universe. The galactic magnetic field accumulates the relativistic CC¯ that eventually annihilate, producing the e −e + pair that give rise to the 511 keV line. Moreover I will discuss how this model can account for the electron recoil excess reported by the XENON1T experiment.