Interpretation of XENON1T excess with MeV boosted dark matter *

Abstract The XENON1T excess of keV electron recoil events may be induced by the scattering electrons and long-lived particles with an MeV mass high speed. We consider a tangible model composed two scalar dark matter (DM) particles, S_B , to interpret via boosted . A small splitting m_{S_A}-m_{S_B}\gt{0} is introduced, can produced using annihilation process S_A^\dagger \to \phi S_B^\dagger resonant ϕ S_B- intermediated vector boson X Although constraints from Big Bang nucleosynthesis, cosmic microwave background (CMB), low-energy experiments set X- mediated cross section \lesssim 10^{-35} \mathrm{cm}^2 scale DM resonance enhanced today still provide sufficient induce excess. relic density significantly reduced s -wave which permitted CMB 21-cm absorption. very fraction compatible stringent bounds on un-boosted -electron in direct detection, also allowed.