Neutrinos from WIMP Annihilations Obtained Using a Full Three-Flavor Monte Carlo Approach

TL;DR

This paper presents an advanced Monte Carlo simulation incorporating full three-flavor neutrino oscillations and interactions to accurately predict neutrino signals from WIMP annihilations in the Sun and Earth, aiding dark matter detection efforts.

Contribution

It introduces a comprehensive three-flavor neutrino oscillation model with interaction effects for WIMP annihilation neutrino yield calculations, and provides publicly available simulation tools.

Findings

Neutrino yields are affected by flavor oscillations and annihilation channels.

Muon neutrino yield can be enhanced or suppressed depending on the WIMP annihilation process.

Oscillation effects are negligible for Earth-based annihilations due to short source-detector distances.

Abstract

Weakly Interacting Massive Particles (WIMPs) are one of the main candidates for the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effects from neutrino interactions on the way through the Sun (absorption, energy loss, and regeneration from tau decays). In addition, we study the effects of non-zero values of the mixing angle $\theta_{13}$ as well as the normal and inverted neutrino mass hierarchies. Our study is performed in an event-based setting which makes these results very useful both for theoretical analyses and for building a neutrino telescope Monte Carlo code. All our results for the neutrino yields, as well as our Monte Carlo code, are publicly available. We find that the yield of muon-type neutrinos from WIMP annihilations in the Sun is enhanced or suppressed, depending on the dominant WIMP annihilation channel. This effect is due to an effective flavor mixing caused by neutrino oscillations. For WIMP annihilations inside the Earth, the distance from source to detector is too small to allow for any significant amount of oscillations at the neutrino energies relevant for neutrino telescopes.