Limits on GeV-scale WIMP Annihilation in Dwarf Spheroidals with IceCube DeepCore

TL;DR

This study uses over seven years of IceCube data to search for neutrinos from low-mass WIMP annihilation in dwarf spheroidal galaxies, setting new upper limits on annihilation cross sections and improving previous constraints.

Contribution

First comprehensive search for neutrinos from low-mass WIMP annihilation in dwarf galaxies using IceCube data, establishing the most stringent limits to date.

Findings

No significant neutrino signal detected.

Set upper limits on WIMP annihilation cross section, improving previous bounds.

Achieved the most restrictive limits for WIMP masses up to 300 GeV.

Abstract

Dark matter is approximately five times more abundant than baryonic matter in the universe, but its physical nature continues to elude physicists. One potential candidate for dark matter is a weakly-interacting massive particle (WIMP), which is predicted by various extensions to the Standard Model (SM) of particle physics. After becoming gravitationally bound in cosmic structures, WIMPs can self-annihilate and produce SM particles including neutrinos, which are observable by detectors like IceCube. We present a search for neutrinos from low-mass $(\leq 300 \, \mathrm{GeV})$ WIMP annihilation in dwarf spheroidal galaxies with over seven years of IceCube livetime. We find no statistically significant evidence of neutrinos produced by WIMP annihilation, and therefore set upper limits on the velocity-averaged annihilation cross section $\left<\sigma v\right>$. Our strongest upper limits at the 90\% confidence level are $\mathcal{O}\!\left(10^{-22} \, \mathrm{{cm}^{3} \, s^{-1}}\right)$ for WIMP annihilation directly into neutrino-antineutrino pairs. For our least sensitive channel, the corresponding limits are $\mathcal{O}\!\left(10^{-20} \, \mathrm{{cm}^{3} \, s^{-1}}\right)$, which is an improvement of over two orders of magnitude over previous IceCube limits from dwarf galaxies at the upper end of our mass range.