Dark Matter Searches for Monoenergetic Neutrinos Arising from Stopped Meson Decay in the Sun

TL;DR

This paper explores the detection of monoenergetic neutrinos from stopped meson decay in the Sun as a novel method to search for dark matter annihilation signals, providing competitive sensitivities for low-mass dark matter.

Contribution

It introduces the consideration of monoenergetic neutrinos from pion and kaon decay in the Sun as a new detection channel for dark matter, improving previous models.

Findings

Liquid scintillation detectors show high sensitivity.

Water Cherenkov detectors provide competitive constraints.

The method is effective for dark matter masses of a few GeV.

Abstract

Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov detectors and find very competitive sensitivities for few-GeV dark matter masses.