Search for electron antineutrino appearance at the △m2□1eV2 Scale

The MiniBooNE Collaboration reports initial results from a search for v̄μ→v̄e oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39×1020 protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200<EvQE<3000MeV: 144 electronlike events have been observed in this energy range, compared to an expectation of 139.2±17.6 events. No significant excess of events has been observed, both at low energy, 200-475MeV, and at high energy, 475-1250MeV. The data are inconclusive with respect to antineutrino oscillations suggested by data from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.