Does the 220 PeV Event at KM3NeT Point to New Physics?

Area of Science:

• Particle Physics
• Astrophysics
• Neutrino Astronomy

Background:

• The KM3NeT experiment detected a high-energy neutrino (100 PeV), significantly more energetic than IceCube's catalog.
• A tension exists between KM3NeT and IceCube observations, with IceCube expected to detect similar events given its capabilities.
• Neutrinos detected by KM3NeT travel through denser matter (rock/sea) than those reaching IceCube (ice), differing by ~133 km.

Purpose of the Study:

• To resolve the tension between KM3NeT and IceCube high-energy neutrino observations.
• To investigate the role of sterile neutrino oscillations in explaining the observed event discrepancy.
• To explore new physics scenarios involving neutrino interactions and matter potentials.

Main Methods:

• Analyzing the difference in neutrino propagation distances for KM3NeT and IceCube.
• Modeling sterile-to-active neutrino oscillations as a potential explanation for the flux difference.
• Examining two specific models: resonance in sterile-to-active transitions via new physics matter potential and nonstandard interactions.

Main Results:

• Sterile-to-active neutrino oscillations at ~100 km scales can increase active neutrino flux near KM3NeT.
• This oscillation mechanism alleviates the tension between the KM3NeT and IceCube observations.
• The findings suggest that neutrino telescopes might be observing evidence of new physics.

Conclusions:

• The observed high-energy neutrino event discrepancy can be explained by sterile neutrino oscillations.
• This phenomenon is relevant at the ~100 km propagation scales relevant to KM3NeT's detection.
• Neutrino telescopes may be on the verge of detecting new fundamental physics beyond the Standard Model.