It looks like the sterile neutrino hypothesized for decades doesn't exist after all.
The search for the mysterious forces that make up the unknown universe has gone dark — at least the search for one particular theoretical quantum particle known as the sterile neutrino. Scientists say in a new study it almost certainly doesn’t exist — with 99 percent certainty, in fact, according to a University of Wisconsin-Madison statement.
The study is based on two years of data from the IceCube Neutrino Observatory at the South Pole, where more than 5,000 light sensors in a cubic kilometer of ice tried to find quantum particles. Had scientists found the sterile neutrino, it would have been the first time something had been found outside of the mathematical system we use. Scientists thought they saw hints of it throughout the years, but never got a full glimpse.
The neutrino itself exist — it’s a very low-mass particle with a neutral charge emitted by the sun or left over from the Big Bang. They rarely interact with physical matter, and thus they simply pass through stars and black holes as if they weren’t even there.
A neutrino can change its type between the three types of neutrinos: tau, electron and muon. Scientists spotted a new oscillation in the 1990s that they couldn’t explain with those three types, and so they hope to explain it with the term “sterile neutrinos” — or neutrinos that don’t interact with anything other than gravity, making it incredibly hard to find them.
Alas, after searching with IceCube, there doesn’t appear to be an evidence that such a neutrino exists.
“This new result highlights the versatility of the IceCube Neutrino Observatory,” according to Olga Botner, a professor of physics and astronomy at Uppsala University in Sweden and the spokesperson for the IceCube Collaboration. “It is not only an instrument for exploration of the violent universe but allows detailed studies of the properties of the neutrinos themselves.”