The Mysterious Origins of the Most Energetic Neutrino Ever Detected

In February 2023, a cosmic particle detector housed deep within the Mediterranean Sea recorded the arrival of a neutrino with roughly 20 to 30 instances extra power than some other neutrino documented beforehand. Labelled KM3-230213A, the particle had a calculated power of 220 petaelectronvolts (PeV), far higher than the ten PeV of the beforehand most energetic neutrino. The discovering generated a whole lot of pleasure amongst physicists, however raised additionally many questions.

Neutrinos are the most abundant particles within the universe with mass. They are a kind of elementary particle, which suggests they don’t break down into smaller constituents, and are due to this fact very small and light-weight. In reality, they’re the lightest of all subatomic particles which have mass. Neutrinos additionally don’t have a cost (in contrast to, say, electrons, one other sort of elementary particle, that are detrimental). As a outcome, solely very not often do neutrinos work together with with different matter; typically they’ll go straight by way of it with out altering it. In reality, trillions of neutrinos travelling by way of area may have handed by way of your physique because you began studying this text. For this purpose neutrinos typically referred to as “ghost particles.”

For particle physicists, the detection of this anomalously energetic neutrino may solely be defined in two methods: Either KM3-230213A was proof of a cosmic course of, probably one by no means witnessed earlier than, with the potential to vary our understanding of neutrinos; or it was a disappointing measurement error. Researchers rapidly set to work to search out out which clarification was true.

Now there appears to be a solution. A complete examine printed within the journal Physical Review X in contrast the info of KM3-230213A with databases of data on different ghost particles which were detected. Having analyzed the out there information, scientists consider that this exceptional, ultra-energetic neutrino was not a statistical phantasm.

But Where Did It Come From?

Just as a rock can’t describe the character of a mountain, a 220 PeV neutrino alone isn’t helpful in explaining the phenomenon that gave rise to it. As the paper acknowledges, with the data out there, it’s not potential to “draw firm conclusions on whether the observation hints at a new ultra-high-energy component in the spectrum.”

But if there have been different recordings of equally energetic neutrinos, this is able to current a considerable advance by hinting that different beforehand unseen phenomena are on the market. “It could mean we are seeing cosmogenic neutrinos for the first time, produced when cosmic rays interacted with the cosmic microwave background, or it could point to a new kind of astrophysical source,” the examine says.

The power of the 2023 neutrino additionally suggests it may have been emitted by one of many highly effective cosmic accelerators that we’re conscious of within the universe: a gamma-ray burst or supernova, or maybe a relativistic jet—a beam of plasma emitted from the neighborhood of a black gap. In distinction, most of the neutrinos detected on Earth are atmospheric neutrinos, produced by the affect of cosmic rays hitting atoms in Earth’s environment, and are far much less energetic. They are the identical particles, however their seemingly origins affect their power.

Different branches of science use and examine neutrinos for various causes. Because neutrinos journey by way of the universe with out being deflected or absorbed, they will present precious details about very distant cosmic occasions. Some scientists consider them as “reporters from the universe” who, on occasion, journey to Earth with information that may in any other case be misplaced.

This story initially appeared on WIRED en Español and has been translated from Spanish.