Boosted dark matter signals uplifted with self-interaction

TL;DR

This paper investigates how dark matter self-interactions can enhance detection signals of boosted dark matter in neutrino detectors, especially through increased capture rates in the Sun, offering promising prospects for future experiments.

Contribution

It demonstrates that dark matter self-interaction significantly boosts detection signals of boosted dark matter in neutrino detectors, a novel insight for non-standard dark sector models.

Findings

Self-interaction enhances dark matter capture in the Sun.

Boosted dark matter signals are detectable at Super-Kamiokande, Hyper-Kamiokande, and PINGU.

Self-interaction effects like evaporation and energy loss are crucial for accurate predictions.

Abstract

We explore detection prospects of a non-standard dark sector in the context of boosted dark matter. We focus on a scenario with two dark matter particles of a large mass difference, where the heavier candidate is secluded and interacts with the standard model particles only at loops, escaping existing direct and indirect detection bounds. Yet its pair annihilation in the galactic center or in the Sun may produce boosted stable particles, which could be detected as visible Cherenkov light in large volume neutrino detectors. In such models with multiple candidates, self-interaction of dark matter particles is naturally utilized in the {\it assisted freeze-out} mechanism and is corroborated by various cosmological studies such as N-body simulations of structure formation, observations of dwarf galaxies, and the small scale problem. We show that self-interaction of the secluded (heavier) dark matter greatly enhances the capture rate in the Sun and results in promising signals at current and future experiments. We perform a detailed analysis of the boosted dark matter events for Super-Kamiokande, Hyper-Kamiokande and PINGU, including notable effects such as evaporation due to self-interaction and energy loss in the Sun.