Overview
- KM3NeT reported KM3-230213A with energy exceeding 100 PeV, and IceCube’s lack of similar events yields a quantified tension of roughly 2–3.5σ.
- The propagation study leverages the longer Earth path to KM3NeT (~147 km of rock and sea versus ~14 km of ice to IceCube) as the key geometric difference.
- Authors propose sterile-neutrino production at the source with conversion to active neutrinos via either a matter-induced resonance or off-diagonal nonstandard interactions over ~100 km.
- The companion cosmogenic analysis fits the event’s 72 PeV–2.6 EeV energy range and finds a single KM3NeT detection would require strongly evolving UHE proton sources, such as high-luminosity AGN.
- Including null results from Pierre Auger and IceCube disfavors such strong source evolution, underscoring that the interpretation remains unsettled pending further detections and cross-observatory checks.