A Search for the Cosmic Ray Boosted Sub-GeV Dark Matter at the PandaX-II Experiment

TL;DR

This paper presents a novel search for sub-GeV dark matter boosted by cosmic rays using the PandaX-II detector, setting new constraints on dark matter-nucleon interactions in previously unexplored parameter space.

Contribution

It introduces a new method utilizing cosmic ray boosting and diurnal modulation to detect sub-GeV dark matter in direct detection experiments.

Findings

Excluded dark matter-nucleon cross sections between 10^{-31} and 10^{-28} cm^2

Constrained dark matter masses from 0.1 MeV/c^2 to 0.1 GeV/c^2

Explored a large parameter space previously untested

Abstract

We report a novel search for the cosmic ray boosted dark matter using the 100~tonne$\cdot$day full data set of the PandaX-II detector located at the China Jinping Underground Laboratory. With the extra energy gained from the cosmic rays, sub-GeV dark matter particles can produce visible recoil signals in the detector. The diurnal modulations in rate and energy spectrum are utilized to further enhance the signal sensitivity. Our result excludes the dark matter-nucleon elastic scattering cross section between 10$^{-31}$cm$^{2}$ and 10$^{-28}$cm$^{2}$ for a dark matter masses from 0.1 MeV/$c^2$ to 0.1 GeV/$c^2$, with a large parameter space previously unexplored by experimental collaborations.