All-flavour Search for Neutrinos from Dark Matter Annihilations in the Milky Way with IceCube/DeepCore

TL;DR

This study uses IceCube's DeepCore detector to search for neutrinos from dark matter annihilations in the Milky Way, setting new limits on dark matter properties despite no detection.

Contribution

First all-flavour neutrino search for dark matter in the Milky Way using IceCube DeepCore, providing improved constraints on dark matter annihilation cross-section.

Findings

No neutrino excess detected, consistent with background.

Set upper limits on dark matter annihilation cross-section, improving previous results.

Demonstrated all-flavour searches are competitive despite cascade resolution challenges.

Abstract

We present the first IceCube search for a signal of dark matter annihilations in the Milky Way using all-flavour neutrino-induced particle cascades. The analysis focuses on the DeepCore sub-detector of IceCube, and uses the surrounding IceCube strings as a veto region in order to select starting events in the DeepCore volume. We use 329 live-days of data from IceCube operating in its 86-string configuration during 2011-2012. No neutrino excess is found, the final result being compatible with the background-only hypothesis. From this null result, we derive upper limits on the velocity-averaged self-annihilation cross-section, < \sigma_A v >, for dark matter candidate masses ranging from 30 GeV up to 10 TeV, assuming both a cuspy and a flat-cored dark matter halo profile. For dark matter masses between 200 GeV and 10 TeV, the results improve on all previous IceCube results on < \sigma_A v >, reaching a level of 10^{-23} cm^3 s^-1, depending on the annihilation channel assumed, for a cusped NFW profile. The analysis demonstrates that all-flavour searches are competitive with muon channel searches despite the intrinsically worse angular resolution of cascades compared to muon tracks in IceCube.