Charm decay in slow-jet supernovae as the origin of the IceCube ultra-high energy neutrino events

We investigate whether the recent ultra-high energy neutrino events detected at the IceCube neutrino observatory could come from the decay of charmed mesons produced within the mildly relativistic jets of supernova-like astrophysical sources. We demonstrate that the allowed region in the astrophysical and QCD parameter spaces permit an explanation of the 5.7σ excess of neutrinos observed by IceCube in the energy range 30 TeV–2 PeV as a diffuse flux of neutrinos produced in such slow-jet supernovae. We discuss the theoretical uncertainties inherent in the evaluation of charm production in high energy hadronic collisions, as well as some of the astrophysical uncertainties associated with slow-jet supernova sources. These sources result in a diffuse neutrino spectrum that exhibits a sharp drop at energies above a few PeV. We incorporate the effect of energy dependence in the spectrum-weighted charm production and decay cross sections and show that this has a very significant effect on the shape, magnitude and cutoff energies for the diffuse neutrino flux