New constraints on the origin of medium-energy neutrinos observed by IceCube
Antonio Capanema, Arman Esmaili, Kohta Murase
Abstract
The recent IceCube publication claims the observation of cosmic neutrinos with energies down to $\ensuremath{\sim}10\text{ }\text{ }\mathrm{TeV}$, reinforcing the growing evidence that the neutrino flux in the 10--100 TeV range is unexpectedly large. Any conceivable source of these neutrinos must also produce a $\ensuremath{\gamma}$-ray flux which degrades in energy en route to the Earth and contributes to the extragalactic $\ensuremath{\gamma}$-ray background measured by the Fermi satellite. In a quantitative multimessenger analysis, featuring minimalistic assumptions, we find a $\ensuremath{\gtrsim}3\ensuremath{\sigma}$ tension in the data, reaching $\ensuremath{\sim}5\ensuremath{\sigma}$ for cosmic neutrinos extended down to $\ensuremath{\sim}1\text{ }\text{ }\mathrm{TeV}$, interpreted as evidence for a population of hidden cosmic-ray accelerators.