Daya Bay find new kind of neutrino transformation

Each antineutrino detector at the Daya Bay Reactor Neutrino Experiment is lined with photomultiplier tubes to catch the faint trace of antineutrino reactions in the scintillator fluids that fill the detectors. Credit: Roy Kaltschmidt, Lawrence Berkeley National Laboratory

(PhysOrg.com) The Daya Bay Reactor Neutrino Experiment, a multinational collaboration operating in the south of China, today reported the first results of its search for the last, most elusive piece of a long-standing puzzle: how is it that neutrinos can appear to vanish as they travel? The surprising answer opens a gateway to a new understanding of fundamental physics and may eventually solve the riddle of why there is far more ordinary matter than antimatter in the universe today.

Traveling at close to the speed of light, the three basic neutrino and their corresponding antineutrinos, mix together and oscillate (transform), but this activity is extremely difficult to detect. From Dec. 24, 2011, until Feb. 17, 2012, scientists observed tens of thousands of interactions of electron antineutrinos, and the data revealed for the first time the strong signal of the effect that the scientists were searching for, a so called "mixing angle" named theta one-three (written θ13). (adapted from PhysOrg)