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 .