Neutrino experiment proves Leggett theory



Science (July 12) -- Data from a massive neutrino experiment show that the elusive subatomic particles must literally be of two mutually exclusive types at once—poking a hole in our intuitive sense of reality. The result is bedrock quantum mechanics. The test with neutrinos involves correlations between measurements separated not in space, but in time. In 1985, theorists Anupam Garg, now at Northwestern University, and physics professor Anthony Leggett of Illinois, considered repeated measurements of a single quantum system: a ring of superconductor in which an unquenchable current flows one way or the other. Now, Joseph Formaggio, a neutrino physicist at the Massachusetts Institute of Technology in Cambridge, and colleagues provide a demonstration using data from the Main Injector Neutrino Oscillation Search experiment at Fermi National Accelerator Laboratory in Batavia, Illinois, which fires neutrinos at near-light-speed 735 kilometers to a 5.4-kiloton detector in the Soudan Mine in Minnesota. Also: ChicagoInno (July 8).