Researchers from the Opera experiment at the Gran Sasso Laboratory in Italy, yesterday announced that they may have spotted their first oscillating neutrino... According to Opera spokesman Antonio Ereditato, confirming the muon-to-tau oscillation rules out the sterile neutrino hypothesis. But he pointed out that this is only Opera's first observed event, with a relatively low confidence level: there is still a 2% chance that their observation is an experimental artifact. “I would bet some money on it, but neither my life nor my scientific reputation” he told Nature. Ereditato will feel much more confident once Opera, which will run until the end of 2012, has spotted another three or four tau neutrinos, he says. The event is so unlikely that scientists do not expect it to happen more than ten times during the experiment's life. more »