Light Dark Matter Detection Prospects at Neutrino Experiments

TL;DR

This paper explores the potential for detecting light dark matter particles via neutrino signals in water Cherenkov and liquid scintillator detectors, highlighting promising detection ranges and methods to distinguish signals from background.

Contribution

It identifies the detection prospects of light dark matter in the 4-10 GeV range using neutrino detectors and proposes specific tests to differentiate signals from atmospheric neutrino backgrounds.

Findings

Liquid scintillator detectors may effectively detect 4-10 GeV dark matter.

Neutrino flavor ratios can help discriminate dark matter signals from background.

Event ratios like R_mu and R_mu_bar can provide insights into dark matter annihilation channels.

Abstract

We consider the prospects for the detection of relatively light dark matter through direct annihilation to neutrinos. We specifically focus on the detection possibilities of water Cherenkov and liquid scintillator neutrino detection devices. We find in particular that liquid scintillator detectors may potentially provide excellent detection prospects for dark matter in the 4-10 GeV mass range. These experiments can provide excellent corroborative checks of the DAMA/LIBRA annual modulation signal, but may yield results for low mass dark matter in any case. We identify important tests of the ratio of electron to muon neutrino events (and neutrino versus anti-neutrino events), which discriminate against background atmospheric neutrinos. In addition, the fraction of events which arise from muon neutrinos or anti-neutrinos ($R_{\mu}$ and $R_{\bar \mu}$) can potentially yield information about the branching fractions of hypothetical dark matter annihilations into different neutrino flavors. These results apply to neutrinos from secondary and tertiary decays as well, but will suffer from decreased detectability.