Collider Constraints on a Dark Matter Interpretation of the XENON1T Excess

TL;DR

This paper investigates collider constraints on a dark matter explanation for the XENON1T excess, focusing on fast-moving DM-electron interactions mediated by a light vector particle, and explores the implications for DM production mechanisms.

Contribution

It derives collider bounds on the DM-electron interaction mediated by a light vector particle, constraining the mediator's mass and couplings relevant to the XENON1T excess.

Findings

Preferred mediator mass is less than 1 GeV.

Vector-electron coupling is much smaller than DM coupling.

Collider bounds restrict possible DM production scenarios.

Abstract

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.