Evidence for neutrino oscillations from the observation ofν¯eappearance in aν¯μbeam

A search for ν̄μ → ν̄e oscillations was conducted by the Liquid Scintillator Neutrino Detector at the Los Alamos Neutron Science Center using ν̄μ from μ + decay at rest. A total excess of 87.9 ± 22.4 ± 6.0 events consistent with ν̄ep → e n scattering was observed above the expected background. This excess corresponds to an oscillation probability of (0.264 ± 0.067 ± 0.045)%, which is consistent with an earlier analysis. In conjunction with other known limits on neutrino oscillations, the LSND data suggest that neutrino oscillations occur in the 0.2 − 10 eV/c ∆m range, indicating a neutrino mass greater than 0.4 eV/c.