C\nu B absorption line in the neutrino spectrum at IceCube

TL;DR

This paper explores the possibility that a gap in the IceCube neutrino spectrum results from an absorption line caused by a new resonance with the cosmic neutrino background, revealing potential new physics beyond the Standard Model.

Contribution

It proposes a novel interpretation of the neutrino spectrum gap as an absorption line from a MeV-scale resonance, linking it to new particles and neutrino properties.

Findings

The neutrino spectrum gap could be explained by an absorption line due to a new resonance.

The absorption feature provides insights into MeV-scale particles and neutrino masses.

Models for the resonance mechanism are discussed.

Abstract

The observed neutrino flux can be as a whole well fitted by a simple power-law of the neutrino energy $E_\nu$, $E_\nu^{-\gamma_\nu}$ ($\gamma_\nu \simeq 2$). As a notable feature of the spectrum, however, it has a gap between 500 TeV and 1 PeV. Although the existence of the gap in the neutrino spectrum is not statistically significant at this point, it is very enticing to ask whether it might hint some physics beyond the Standard Model. In this paper, we investigate a possibility that the gap can be interpreted as an absorption line in the power-law spectrum by the cosmic neutrino background through a new resonance in the MeV range. We also show that the absorption line has rich information about not only the MeV scale new particle but also the neutrino masses as well as the distances to the astrophysical sources of the high energy neutrinos. Viable models to achieve this possibility are also discussed.