CERN Set to Study Sterile Neutrinos
by Edwin Cartlidge on 5 February 2013
A new experimental facility to detect a hypothetical particle that many physicists think probably doesn't exist could be up and running at the CERN laboratory near Geneva, Switzerland, within 3 years, assuming that the lab's member states approve spending roughly $110 million to build it.
The sterile neutrino, if it exists, would be an obscure variety of an already otherworldly subatomic particle. Ordinary neutrinos, which have no charge and almost no mass, come in three varieties: electron, muon, and tau. They are very hard to detect because their interaction with ordinary matter is extremely feeble, but over the years physicists have detected enough of them to observe that as they travel through space they can "oscillate" from one flavour to another.
This oscillation phenomenon, which means that neutrinos cannot be entirely massless, has been confirmed by many different experiments. But one such experiment produced results at odds with the rest. That was the Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos National Laboratory in New Mexico, which in data acquired between 1993 and 1998 showed muon antineutrinos to be oscillating into electron antineutrinos far more readily than expected.