On-shell mediator dark matter models and the Xenon1T excess *
Mingxuan Du, Jinhan Liang, Zuowei Liu, Van Que Tran, Yilun Xue
Abstract
Abstract We present a dark matter model to explain the excess events in the electron recoil data recently reported by the Xenon1T experiment. In our model, dark matter annihilates into a pair of on-shell particles , which subsequently decay into the final state; interacts with electrons to generate the observed excess events. Because of the mass hierarchy, the velocity of can be rather large and can have an extended distribution, providing a good fit to the electron recoil energy spectrum. We estimate the flux of from dark matter annihilations in the galaxy and further determine the interaction cross section, which is sizable but sufficiently small to allow to penetrate the rocks to reach the underground labs.