Recently, the KM3NeT experiment reported the detection of a neutrino with exceptionally high energy E = 220 PeV, whose origin remains unclear. The corresponding value of the neutrino flux is in tension with the results of other high-energy neutrino experiments. In this study, we discuss the possibility that this neutrino is cosmogenic, i.e., produced by ultra-high energy cosmic rays during their propagation through the intergalactic medium. We adopt the ultra-high energy cosmic rays flux models derived by the Telescope Array experiment, which features a predominantly light mass composition. We show that the predictions of the cosmogenic neutrino flux in these models are consistent with the measurements of the KM3NeT-only and with that of the “global neutrino observatory” at approximately 2σ level. Notably, this result is achieved in a minimal version of the ultra-high energy cosmic rays flux models, that assume one source population with a standard cosmological evolution. We also estimate the corresponding cosmogenic gamma-ray flux and show that it is consistent with Fermi-LAT Isotropic Diffuse Gamma-Ray Background measurements and ultra-high energy gamma-ray limits; the improvement of the latter can probe these predictions in future.
Kuznetsov et al. (2026) studied this question.