Search for Neutrino Oscillations at the Palo Verde Nuclear Reactors

Abstract

We report on the initial 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 to better than 5%, excluding at 90% CL $\rm\barν_e - \barν_x$ oscillations with $Δm^2 > 1.12\times 10^{-3}$ eV^2 for maximal mixing and $\sin^2{2θ} > 0.21$ for large $Δm^2$.