Could a Primordial Black Hole Explosion Explain the extremely high-energy KM3NeT neutrino Event?

TL;DR

This paper investigates whether a primordial black hole explosion could explain a high-energy neutrino event, analyzing multi-messenger signals and concluding that such an explanation is unlikely given the lack of accompanying gamma-ray and cosmic-ray detections.

Contribution

The study provides a detailed analysis of the multi-messenger signals expected from a nearby PBH explosion and challenges the PBH explosion hypothesis for the KM3NeT neutrino event.

Findings

No gamma-ray or cosmic-ray signals detected that would support PBH explosion hypothesis.

Expected signals in gamma-ray and neutrino observatories are inconsistent with the observed event.

PBH explosion scenario is strongly disfavored by the absence of multi-messenger signals.

Abstract

A black hole is expected to end its lifetime in a cataclysmic runaway burst of Hawking radiation, emitting all Standard Model particles with ultra-high energies. Thus, the explosion of a nearby primordial black hole (PBH) has been proposed as a possible explanation for the $\sim 220$~PeV neutrino-like event recently reported by the KM3NeT collaboration. If the event originated from a PBH, the source would need to lie at $(1-7)\times 10^{-5} \mathrm{pc}$ - depending on the assumed effective area - thus within the Solar System. At such proximity, the resulting flux of gamma rays and cosmic rays would be detectable at Earth. By incorporating the time-dependent field of view of gamma-ray observatories, we show that LHAASO should have recorded $\mathcal{O}(10^8)$ events between fourteen and seven hours prior to the KM3NeT detection. IceCube and KM3NeT \textit{itself} should likewise have detected of order a few hundred events in the range $1~\mathrm{TeV} \lesssim E_\nu \lesssim 1~\mathrm{PeV}$ during the 24 hours preceding the burst. The absence of any such multi-messenger signal, particularly in gamma-ray data, strongly disfavors the interpretation of the KM3-230213A event as arising from evaporation in a minimal four-dimensional Schwarzschild scenario.