Invisible Neutrino Decay Could Resolve IceCube's Track and Cascade Tension.

Area of Science:

• Particle Physics and Astrophysics
• Cosmic Neutrino Detection

Background:

• The IceCube Neutrino Observatory distinguishes high-energy astrophysical neutrinos via track and cascade event topologies.
• Differences in flavor composition between tracks and cascades offer insights into neutrino properties and astrophysical production mechanisms.

Purpose of the Study:

• To investigate the tension between IceCube's track and cascade data under conventional neutrino production models.
• To explore the hypothesis of invisible neutrino decay as a solution to this observed tension.

Main Methods:

• Analysis of IceCube high-energy neutrino event data, specifically tracks and cascades.
• Comparison of observed data with predictions from standard neutrino production models.
• Modeling of invisible neutrino decay scenarios with a specific lifetime (τ/m=10^2 s/eV).

Main Results:

• A >3σ tension exists between IceCube track and cascade datasets assuming conventional neutrino production.
• Invisible neutrino decay with τ/m=10^2 s/eV resolves this tension, improving the fit by >3σ.
• This decay model aligns with all other multimessenger observations.
• The model predicts a 59% reduction in tau neutrino (ντ) events, consistent with the observed deficit.

Conclusions:

• Invisible neutrino decay is a compelling explanation for the observed discrepancy in IceCube data.
• This scenario reconciles different event topologies and aligns with broader astrophysical observations.
• The model's prediction of reduced tau neutrino events warrants further investigation.