In astrophysics, extreme events may call for extreme interpretations. Sometimes, that means weighing every possible option for what something could have been\u2014or what it could explain.<\/p>\n
In 2023, a detector buried off the Mediterranean Sea spotted an impossibly powerful neutrino signal\u2014tens of thousands of times more energetic than anything produced by humanity\u2019s most powerful particle accelerators. But the signal raised more questions than answers, particularly with regard to its origins. Now, one team offers an ambitious solution: the explosion of primordial black holes leaking dark electrons.<\/p>\n
A Physical Review Letters<\/a> paper on the proposal, set for publication\u00a0on February 10, is currently available as a preprint on arXiv<\/a>.<\/p>\n \u201cAt the moment, no one knows what actually caused this neutrino\u2014our proposal is one possibility,\u201d Andrea Thamm<\/a>, study senior author and a particle physicist at the University of Massachusetts Amherst, told Gizmodo. \u201cWith time we may observe more highly energetic particles\u2014or not\u2014and this will inform whether our proposal is right.\u201d<\/p>\n The most powerful \u201cghost particle\u201d <\/p>\n Trillions of neutrinos\u2014nearly massless, neutrally charged particles\u2014pass through us every second, but we only acknowledge their existence when these so-called \u201cghost particles\u201d slam against the many giant neutrino detectors on Earth.<\/p>\n In February 2023, a neutrino of undefined origins entered the detection range of the European neutrino facility KM3NeT, located off the coast of Malta in the Mediterranean. The tiny particle\u2019s energy level was unfathomably large\u2014roughly 30,000 times higher<\/a> than any particle produced by CERN\u2019s Large Hadron Collider, the world\u2019s most powerful accelerator.<\/p>\n \u201cIt was not expected that such a high-energy neutrino would be seen, and there were no known astrophysical sources,\u201d Thamm noted.<\/p>\n Indeed, the signal was an enigma to physicists for a variety of reasons. For one, the neutrino only appeared to KM3NeT, but not to experiments like IceCube. In fact, the similarly capable detector \u201cnot only didn\u2019t register the event [but] had never clocked anything with even one hundredth of its power,\u201d the researchers explained in a statement<\/a>.<\/p>\n To see the invisible, try the impossible <\/p>\n