New constraints on muon-neutrino to electron-neutrino transitions in MINOS

This paper reports results from a search for ${\ensuremath{\nu}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{e}$ transitions by the MINOS experiment based on a $7\ifmmode\times\else\texttimes\fi{}{10}^{20}$ protons-on-target exposure. Our observation of 54 candidate ${\ensuremath{\nu}}_{e}$ events in the far detector with a background of $49.1\ifmmode\pm\else\textpm\fi{}7.0(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}2.7(\mathrm{syst})$ events predicted by the measurements in the near detector requires $2{sin}^{2}(2{\ensuremath{\theta}}_{13}){sin}^{2}{\ensuremath{\theta}}_{23}<0.12(0.20)$ at the 90% C.L. for the normal (inverted) mass hierarchy at ${\ensuremath{\delta}}_{CP}=0$. The experiment sets the tightest limits to date on the value of ${\ensuremath{\theta}}_{13}$ for nearly all values of ${\ensuremath{\delta}}_{CP}$ for the normal neutrino mass hierarchy and maximal ${sin}^{2}(2{\ensuremath{\theta}}_{23})$.