Search for neutrino oscillations at the Palo Verde Nuclear reactors

Abstract We report on the results from a measurement of the anti-neutrino flux and spectrum at a distance of about 800 m from the three reactors of the Palo Verde Nuclear Generating Station using a segmented gadolinium-loaded scintillation detector. We find that the anti-neutrino flux agrees with that predicted in the absence of oscillations, excluding at 90% CL ν e − ν x oscillations with Δ m 2 > 1.12 × 10 −3 eV 2 for maximal mixing and sin 2 2θ > 0.21 for large Δ m 2 . Our results support the conclusion that the atmospheric neutrino oscillations observed by Super-Kamiokande do not involve ν e .