Boosted Dark Matter Quarrying at Surface Neutrino Detectors

TL;DR

This paper introduces 'Earth Shielding' as a method to improve detection of boosted dark matter at surface neutrino detectors by using the Earth to block cosmic-ray backgrounds, enhancing sensitivity to otherwise challenging signals.

Contribution

It proposes a novel background suppression technique for surface detectors, enabling them to detect featureless boosted dark matter signals from the Galactic Center.

Findings

Surface detectors can achieve high sensitivity to boosted dark matter signals.

Earth shielding effectively reduces cosmic-ray backgrounds in surface experiments.

Validated potential of surface detectors like MicroBooNE and ProtoDUNE for dark matter searches.

Abstract

We propose the idea of "Earth Shielding" to reject cosmic-ray backgrounds, in the search for boosted dark matter at surface neutrino detectors, resulting in the enhancement of the signal-to-background ratio. The identification of cosmic-originating rare signals, especially lacking features, at surface detectors is often considered hopeless due to a vast amount of cosmic-ray-induced background, hence underground experiments are better motivated to avoid such a challenge. We claim that surface detectors can attain remarkable sensitivities to even featureless signals, once restricting to events coming through the Earth from the opposite side of the detector location for the signals leaving appreciable tracks from which the source direction is inferred. By doing so, potential backgrounds in the signal region of interest can be substantially suppressed. To validate our claim, we study experimental reaches at several surface experiments such as SBN Program (MicroBooNE, ICARUS, and SBND) and ProtoDUNE for elastic boosted dark matter signatures stemming from the Galactic Center. We provide a systematic discussion on maximizing associated signal sensitivities.