Description:

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 ~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) x 10^-5 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 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 TeV E_nu < 1 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. 

Lua Airoldi, Visiting Student (University of Sao Paulo), Fermilab

Host: Adrian Thompson