Search for muon-neutrino to electron-neutrino transitions in MINOS

Abstract

This letter reports on a search for $\hat{I}{½}_{\hat{I}}¼\to \hat{I}{½}_e$ transitions by the MINOS experiment based on a \unit[$3.14\times 10^{20}$]{protons-on-target} exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of $27\pm 5 {\rm (stat.)} \pm 2 {\rm (syst.)$ events predicted by the measurements in the Near Detector. If interpreted in terms of $\hat{I}{½}_{\hat{I}}¼\to \hat{I}{½}_e$ oscillations, this 1.5 $\ddot{I}ƒ$ excess of events is consistent with ${\sin }^2(2\hat{I}{¸}_{13})$ comparable to the CHOOZ limit when $|\delmsq{}|$=\unit[2.43$\times 10^{-3}$] {$\mathrm{e}{\mathrm{V}}^2$} and \sinsq{23}=1.0 are assumed.

5 pages, 4 figures, submitted to Phys. Rev. Lett