Search for neutrinos from decaying dark matter with IceCube

TL;DR

This paper reports on two IceCube analyses searching for neutrinos from decaying dark matter, setting the strongest constraints to date on dark matter particle lifetimes above 10 TeV, with no significant excess observed.

Contribution

The study provides the first combined analysis of muon track and cascade events to constrain dark matter decay, improving lifetime limits for PeV-mass dark matter particles.

Findings

No significant neutrino excess from dark matter decay observed.

Established lower lifetime limits of 10^{28} seconds for dark matter masses above 10 TeV.

Set the most stringent constraints to date on decaying dark matter models.

Abstract

With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses six years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses two years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: We obtain the strongest constraint to date, excluding lifetimes shorter than $10^{28}\,$s at $90\%$ CL for dark matter masses above $10\,$TeV.