Collider Constraints on a Dark Matter Interpretation of the XENON1T
  Excess
  In light of the excess in the low-energy electron recoil events reported by
XENON1T, many new physics scenarios have been proposed as a possible origin of
the excess. One possible explanation is that the excess is a result of a fast
moving dark matter (DM), with velocity $v\sim0.05-0.20$ and mass between 1 MeV
and 10 GeV, scattering off an electron. Assuming the fast moving DM-electron
interaction is mediated by a vector particle, we derive collider constraints on
the said DM-electron interaction. The bounds on DM-electron coupling is then
used to constrain possible production mechanisms of the fast moving DM. We find
that the preferred mass of the vector mediator is relatively light ($\lesssim$
1 GeV) and the coupling of the vector to the electron is much smaller than the
coupling to the fast moving DM.
