Invisible Neutrino Decay Resolves IceCube's Track and Cascade Tension

TL;DR

The paper proposes that invisible neutrino decay explains the discrepancy between track and cascade neutrino observations in IceCube, improving data fit and aligning with other observations.

Contribution

It introduces a neutrino decay model that resolves the tension between IceCube's track and cascade data, a novel explanation not previously considered.

Findings

Decay model improves data fit by over 3σ

Predicts 59% reduction in tau neutrino events

Consistent with multi-messenger observations

Abstract

The IceCube Neutrino Observatory detects high energy astrophysical neutrinos in two event topologies: tracks and cascades. Since the flavor composition of each event topology differs, tracks and cascades can be used to test the neutrino properties and the mechanisms behind the neutrino production in astrophysical sources. Assuming a conventional model for the neutrino production, the IceCube data sets related to the two channels are in $>3\sigma$ tension with each other. Invisible neutrino decay with lifetime $\tau/m=10^2$ s/eV solves this tension. Noticeably, it leads to an improvement over the standard non-decay scenario of more than $3\sigma$ while remaining consistent with all other multi-messenger observations. In addition, our invisible neutrino decay model predicts a reduction of $59\%$ in the number of observed $\nu_\tau$ events which is consistent with the current observational deficit.