Paper detail

Event Excess in the MiniBooNE Search for $\bar ν_μ\rightarrow \bar ν_e$ Oscillations

The MiniBooNE experiment at Fermilab reports results from a search for $\bar ν_μ\rightarrow \bar ν_e$ oscillations, using a data sample corresponding to $5.66 \times 10^{20}$ protons on target. An excess of $20.9 \pm 14.0$ events is observed in the energy range $475<E_ν^{QE}<1250$ MeV, which, when constrained by the observed $\bar ν_μ$ events, has a probability for consistency with the background-only hypothesis of 0.5\%. On the other hand, fitting for $\barν_μ\rightarrow\barν_e$ oscillations, the best-fit point has a $χ^2$-probability of 8.7\%. The data are consistent with $\bar ν_μ\rightarrow \bar ν_e$ oscillations in the 0.1 to 1.0 eV$^2$ $Δm^2$ range and with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory.