Directional Searches at DUNE for Sub-GeV Monoenergetic Neutrinos Arising from Dark Matter Annihilation in the Sun

TL;DR

This paper explores how directional detection of sub-GeV neutrinos at DUNE can improve the search for dark matter annihilation signals in the Sun by distinguishing signal from background.

Contribution

It introduces the use of neutrino track directionality at DUNE to enhance detection of dark matter-induced neutrinos from the Sun.

Findings

Directional information can increase signal-to-background ratio by up to 5 times.

Neutrino-induced proton tracks are highly forward-peaked, aiding in signal discrimination.

Method improves sensitivity to dark matter annihilation signals in the Sun.

Abstract

We consider the use of directionality in the search for monoenergetic sub-GeV neutrinos arising from the decay of stopped kaons, which can be produced by dark matter annihilation in the core of the Sun. When these neutrinos undergo charged-current interactions with a nucleus at a neutrino detector, they often eject a proton which is highly peaked in the forward direction. The direction of this track can be measured at DUNE, allowing one to distinguish signal from background by comparing on-source and off-source event rates. We find that directional information can enhance the signal to background ratio by up to a factor of 5.