Interpreting IceCube 6-year HESE data as an evidence for hundred TeV decaying Dark Matter

TL;DR

This paper suggests that the excess of neutrino events observed by IceCube in the 40-200 TeV range can be explained by decaying dark matter, challenging the single astrophysical source hypothesis.

Contribution

It introduces a decaying dark matter model to interpret IceCube neutrino data, providing a better fit than single-component astrophysical models.

Findings

Up to 2.6 sigma excess in 40-200 TeV neutrino events

Decaying dark matter offers a plausible explanation for the excess

Likelihood analysis supports the two-component scenario

Abstract

The assumption of a single astrophysical power-law flux to explain the IceCube 6-year HESE extraterrestrial events yields a large spectral index that is in tension with gamma-ray observations and the 6-year up-going muon neutrinos data. Adopting a spectral index belonging to the range $\left[2.0,2.2\right]$, which is compatible with the one deduced by the analysis performed on the 6-year up-going muon neutrinos data and with $p$-$p$ astrophysical sources, the latest IceCube data show an up to $2.6\,\sigma$ excess in the number of events in the energy range 40--200 TeV. We interpret such an excess as a decaying Dark Matter signal and we perform a likelihood-ratio statistical test to compare the two-component scenario with respect to the single-component one.