Limits on Sub-GeV Dark Matter from the PROSPECT Reactor Antineutrino Experiment

TL;DR

This paper presents a novel search for sub-GeV dark matter upscattered by cosmic rays using the PROSPECT reactor antineutrino experiment, setting new constraints on dark matter with large interaction cross-sections.

Contribution

It introduces a new method to detect boosted sub-GeV dark matter via cosmic ray upscattering and analyzes diurnal modulation to improve constraints.

Findings

Set new limits on sub-GeV dark matter interactions

Detected characteristic diurnal sidereal modulation

Excluded parameter space for large cross-section dark matter

Abstract

If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscattered by cosmic rays using the PROSPECT reactor antineutrino experiment. We show that such a flux of upscattered dark matter would display characteristic diurnal sidereal modulation, and use this to set new experimental constraints on sub-GeV dark matter exhibiting large interaction cross-sections.