Hunting for bumps in the diffuse high-energy neutrino flux

TL;DR

This paper searches for bump-like features in the high-energy neutrino spectrum to identify astrophysical sources, constrains candidate populations with current data, and forecasts improved detection prospects with future telescopes.

Contribution

It introduces a method to detect spectral bumps in neutrino data and provides constraints on source models, with forecasts for future detection capabilities.

Findings

No evidence of spectral bumps in current data.

Constraints placed on candidate neutrino sources.

Future telescopes could enable decisive discovery or tighter constraints.

Abstract

The origin of the TeV--PeV astrophysical neutrinos seen by the IceCube telescope is unknown. If they are made in proton-photon interactions in astrophysical sources, their spectrum may show bump-like features. We search for such features in the 7.5-years High-Energy Starting Events (HESE), and forecast the power of such searches using larger data samples expected from upcoming telescopes. Present-day data reveals no evidence of bump-like features, which allows us to constrain candidate populations of photohadronic neutrino sources. Near-future forecasts show promising potential for stringent constraints or decisive discovery of bump-like features. Our results provide new insight into the origins of high-energy astrophysical neutrinos, complementing those from point-source searches.