Proposed search for a fourth neutrino with a PBq antineutrino source.

Several observed anomalies in neutrino oscillation data can be explained by a hypothetical fourth neutrino separated from the three standard neutrinos by a squared mass difference of a few eV 2 . We show that this hypothesis can be tested with a PBq (ten kilocurie scale) 144 Ce or 106 Ru antineutrino �-source deployed at the center of a large low background liquid scintillator detector. In particular, the compact size of such a source could yield an energy-dependent oscillating pattern in event spatial distribution that would unambiguously determine neutrino mass differences and mixing angles. Most results from neutrino experiments over the last twenty years can be quite accurately described