We show that the electron recoil excess around 2 keV claimed by the Xenon collaboration can be fitted by DM or DM-like particles having a fast component with velocity of order ∼0.1. Those particles cannot be part of the cold DM halo of our Galaxy, so we speculate about their possible nature and origin, such as fast moving DM sub-haloes, semi-annihilations of DM and relativistic axions produced by a nearby axion star. Feasible new physics scenarios must accommodate exotic DM dynamics and unusual DM properties.
@article{arxiv.2006.10735,
title = {Dark Matter and the XENON1T electron recoil excess},
author = {Kristjan Kannike and Martti Raidal and Hardi Veermäe and Alessandro Strumia and Daniele Teresi},
journal= {arXiv preprint arXiv:2006.10735},
year = {2020}
}