Recently the ARCA array detector published the down-ward-horizontal event: the KM3-230213A.
It appeared as the most energetic neutrino ever observed: about 200 PeV (2 · 1017 eV ) up to EeV
(1018 eV) energy. This huge value, is puzzling. It is not statistically consistent with several upper
bound derived by two greater and longer life detectors: by ICECUBE and in particular by AUGER
array. Asymmetry in recent ICECUBE neutrino alert tracks upward and downward at same
horizontal angles as ARCA one, suggest that they are mostly polluted atmospheric muon bundles.
This paucity also disfavor the skimming neutrino interpretation by ARCA. We suggest that the
array floating and bending in the deep sea may lead, sometime, to a misleading geometry that is
pointing to a wrong arrival angle direction: a much less horizontal muon (neutrino) track respect
to a much real one, more inclined and vertical, due to atmospheric muon bundle or charmed single
event. Contrary to present argument, if such a rare event would be soon rediscovered in data or
re-observed, it would open the road to a new guaranteed Tau neutrino Astronomy. At EeV energy
such upward tau air-showers should shine AUGER telescopes or blaze future satellite in Space.
A previous model in astrophysics considered energetic 𝐸 𝜈 >> 100 EeV, neutrino scattering, onto
cosmic, relic, light mass ones. Their ultra-relativistic Z boson resonance formation and its decay
in flight would produce hadron UHECR relics around tens-hundred EeV energy. Explaining how
sources located at far distances, above the usual GZK hundred Mpc, cut off ones, may shine and
cluster in AUGER or TA data.