Use of ANTARES and IceCube Data to Constrain a Single Power-law Neutrino Flux

Abstract

We perform the first statistical combined analysis of the diffuse neutrino flux observed by ANTARES (nine-year) and IceCube (six-year) by assuming a single astrophysical power-law flux. The combined analysis reduces by a few percent the best-fit values for the flux normalization and the spectral index. Both data samples show an excess in the same energy range (40-200 TeV), suggesting the presence of a second component. We perform a goodnessof-fit test to scrutinize the null assumption of a single power-law, scanning different values for the spectral index. The addition of the ANTARES data reduces the p-value by a factor 2 3 . In particular, a single power-law component in the neutrino flux with the spectral index deduced by the six-year up-going muon neutrinos of IceCube is disfavored with a p-value smaller than 10 −2 .

Potential Dark Matter Signals at Neutrino Telescopes

“…Different analyses investigating the scenario with two astrophysical power-law components have pointed out that the data are compatible with the sum of a hard isotropic extragalactic neutrino flux and an additional softer one with a potential galactic origin (see, for example, Ref.s [20,21,22,23]). Moreover, the two-component hypothesis is also supported by the first combined analysis of IceCube and ANTARES data [24]. Remarkably, both IceCube and ANTARES telescopes have measured in the same energy range (about 40-200 TeV) a slight excess with respect to an astrophysical power-law flux deduced by TG data (γ Astro ≤ 2.2), after the background subtraction [24,25,26,27].…”

“…Moreover, the two-component hypothesis is also supported by the first combined analysis of IceCube and ANTARES data [24]. Remarkably, both IceCube and ANTARES telescopes have measured in the same energy range (about 40-200 TeV) a slight excess with respect to an astrophysical power-law flux deduced by TG data (γ Astro ≤ 2.2), after the background subtraction [24,25,26,27].…”

Decaying dark matter at IceCube and its signature on High Energy gamma experiments

“…This two-component hypothesis is at the same time supported by the first combined analysis of IceCube and ANTARES data [34]. It turns out that both IceCube and ANTARES telescopes have measured in the same energy range (about 40-200 TeV) a slight excess with respect to an astrophysical power-law flux deduced by TG data (γ ≤ 2.2), after the background subtraction [34][35][36][37].An alternative source for this diffuse UHE neutrino flux is decaying Dark Matter (DM) . While another available source might be identified with annihilating DM [33,35,39,[63][64][65][66][67], the unitarity limit leads in general to small neutrinos fluxes which are therefore not detectable.…”

A search for dark matter in the Galactic halo with HAWC

“…Accordingly, a number of models have been developed which explain the high-energy neutrino flux with DM [7,. Generally these models seek to explain the highest energy neutrinos observed by IceCube -the so-called High Energy Starting Events (HESE)-however some also deal with a putative excess in the lower energy Medium Energy Starting Events (MESE) [45], which has been discussed in the context of DM [46] and astrophysics [47][48][49]. Nevertheless, in these models the DM decays will generically also produce photons which can be searched for in other experiments.…”