Probing the Dark Matter mass and nature with neutrinos

TL;DR

This study evaluates the potential of next-generation neutrino detectors to identify dark matter properties, such as mass and annihilation channels, by analyzing neutrino signals from dark matter annihilations inside the Sun.

Contribution

It demonstrates that future neutrino detectors can accurately measure dark matter mass and distinguish annihilation channels, improving upon current bounds.

Findings

Detectors can precisely measure dark matter mass if annihilation involves neutrino or tau channels.

Degeneracies exist where different masses and channels produce similar signals.

Sensitivity to branching ratios exceeds current bounds by one to two orders of magnitude.

Abstract

We study the possible indirect neutrino signal from dark matter annihilations inside the solar interior for relatively light dark matter masses in the O(10) GeV range. Due to their excellent energy reconstruction capabilities, we focus on the detection of this flux in liquid argon or magnetized iron calorimeter detectors, proposed for the next generation of far detectors of neutrino oscillation experiments and neutrino telescopes. The aim of the study is to probe the ability of these detectors to determine fundamental properties of the dark matter nature such as its mass or its relative annihilation branching fractions to different channels. We find that these detectors will be able to accurately measure the dark matter mass as long as the dark matter annihilations have a significant branching into the neutrino or at least the tau channel. We have also discovered degeneracies between different dark matter masses and annihilation channels, where a hard tau channel spectrum for a lower dark matter mass may mimic that of a softer quark channel spectrum for a larger dark matter mass. Finally, we discuss the sensitivity of the detectors to the different branching ratios and find that it is between one and two orders of magnitude better than the current bounds from those coming from analysis of Super-Kamiokande data.