An Alternative Analysis of the LSND Neutrino Oscillation Search Data onν¯μ→ν¯e

This analysis of data from the Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson Physics Facility (LAMPF) sets bounds on neutrino oscillations in the appearance channel ${\overline{\nu }}_{\mu }\to {\overline{\nu }}_e$ by searching for the signature of the reaction ${\overline{\nu }}_{e}p\to e^{+}n$: an $e^{+}$ followed by a 2.2 MeV $\gamma$ ray from neutron capture. Five $e^{\pm }$- $\gamma$ coincidences are observed in time with the LAMPF beam, with an estimated background of 6.2 events. The 90% confidence limits obtained in this analysis are $\Delta m^2<0.07\mathrm{}{\mathrm{eV}}^2$ for ${sin}^{2}2\theta =1\mathrm{}$, and ${sin}^{2}2\theta <6\mathrm{}\times {10}^{-3\mathrm{}}$ for $\Delta m^2\gtrsim 20{\mathrm{eV}}^2$. The possible signal at the edge of the detector's sensitivity is mentioned.