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

TL;DR

This paper proposes that neutrinos detected by IceCube from 30 TeV to 2 PeV originate from charm meson decay in slow-jet supernovae, explaining the observed excess and spectral features.

Contribution

It introduces a model linking charm decay in slow-jet supernovae to IceCube neutrino observations, accounting for spectral cut-offs and uncertainties.

Findings

Explains IceCube neutrino excess with charm decay in supernova jets.

Accounts for spectral cut-off above a few PeV due to proton cooling.

Shows energy dependence of charm production significantly affects neutrino flux.

Abstract

We investigate whether the recent ultra-high energy (UHE) 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 $5.7\sigma$ excess of neutrinos observed by IceCube in the energy range 30 TeV--2 PeV can be explained by a diffuse flux of neutrinos produced in such slow-jet supernovae, using the values of astrophysical and QCD parameters within the theoretical uncertainties associated with neutrino production from charmed meson decay in astrophysical sources. We discuss the theoretical uncertainties inherent in the evaluation of charm production in high energy hadronic collisions, as well as the astrophysical uncertainties associated with slow-jet supernova sources. The proton flux within the source, and therefore also the produced neutrino flux, is cut off at around a few PeV, when proton cooling processes become dominant over proton acceleration. This directly explains the sudden drop in event rates at energies above a few PeV. We incorporate the effect of energy dependence in the spectrum-weighted charm production cross-section and show that this has a very significant effect on the shape, magnitude and cut-off energies for the neutrino flux.