Limits on neutrino oscillations from the CHOOZ experiment

We present new results based on the entire CHOOZ (The CHOOZ experiment is named after the new nuclear power station operated by Electricite de France (EdF) near the village of Chooz in the Ardennes region of France) data sample. We find (at 90% confidence level) no evidence for neutrino oscillations in the (v) over bar(e) disappearance mode, for the parameter region given by approximately delta m(2) > 7.10(-4) eV(2) for maximum mixing, and sin(2)2 theta = 0.10 for large delta m(2). Lower sensitivity results, based only on the comparison of the positron spectra from the two different-distance nuclear reactors, are also presented; these are independent of the absolute normalization of the (v) over bar(e) flux, the cross section, the number of target protons and the detector efficiencies. (C) 1999 Elsevier Science B.V. All rights reserved.