Neutrino search finds no evidence of “hidden” particle
An exhaustive search for a ghostly subatomic particle called the sterile neutrino has come up empty, weakening the case for its existence. Scientists from MIT and the University of Wisconsin at Madison, along with 40 other institutions, report today in Physical Review Letters that after analyzing 20,000 neutrinos detected over the span of a year at the IceCube Neutrino Observatory at the South Pole, they were unable to observe any sign of sterile, or “hidden,” neutrinos. Sterile neutrinos are hypothetical particles that may behave in ways that cannot be explained by the standard rules of physics. They are thought to have no interactions and thus to be completely “sterile” to physical matter — a quality that allows these particles to stream uninhibited and undetected through the universe. If they exist, scientists believe sterile neutrinos may be at the root of a number of cosmological mysteries, including dark matter, which makes up roughly...