Dark Matter interpretation of low energy IceCube MESE excess

TL;DR

This paper explores the possibility that the low-energy excess of IceCube neutrino events can be explained by Dark Matter decay or annihilation, achieving a statistical significance of up to 3.9 sigma.

Contribution

It introduces a two-component model combining astrophysical neutrinos and Dark Matter signals to explain the IceCube excess, considering various Dark Matter scenarios.

Findings

Dark Matter interpretation improves fit significance up to 3.9σ.

Both decaying and annihilating Dark Matter scenarios are compatible.

The model suggests Dark Matter could contribute to the observed neutrino excess.

Abstract

The 2-years MESE IceCube events show a slightly excess in the energy range 10-100 TeV with a maximum local statistical significance of 2.3$\sigma$, once a hard astrophysical power-law is assumed. A spectral index smaller than 2.2 is indeed suggested by multi-messenger studies related to $p$-$p$ sources and by the recent IceCube analysis regarding 6-years up-going muon neutrinos. In the present paper, we propose a two-components scenario where the extraterrestrial neutrinos are explained in terms of an astrophysical power-law and a Dark Matter signal. We consider both decaying and annihilating Dark Matter candidates with different final states (quarks and leptons) and different halo density profiles. We perform a likelihood-ratio analysis that provides a statistical significance up to 3.9$\sigma$ for a Dark Matter interpretation of the IceCube low energy excess.