Constraints on electron-scattering interpretation of XENON1T excess

TL;DR

This paper examines whether electron scattering by a boosted particle can explain the XENON1T excess, analyzing cosmological, astrophysical, and experimental constraints to assess the viability of this interpretation.

Contribution

The study provides a comprehensive analysis of constraints on electron scattering explanations for the XENON1T excess, highlighting the challenges in reconciling this interpretation with existing bounds.

Findings

Constraints from big-bang nucleosynthesis limit particle properties.

Supernova cooling bounds restrict particle-electron interactions.

Direct detection experiments impose additional limits.

Abstract

Recently, the XENON1T experiment has observed an excess in the electronic recoil data in the recoil energy range of $1$-$7$ keV. One of the most favored new physics interpretations is electron scattering with a boosted particle with a velocity of $\sim 0.1$ and a mass of $\gtrsim 0.1\,\mathrm{MeV}$. If such a particle has a strong interaction with electrons, it may affect the standard scenario of cosmology or be observed at low-threshold direct detection experiments. We study various constraints, mainly focusing on those from the big-bang nucleosynthesis, supernova cooling, and direct detection experiments. We discuss the implication of these constraints on electron-scattering interpretation of the XENON1T excess.