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

TL;DR

This paper reports on the MINOS experiment's search for muon-neutrino to electron-neutrino oscillations, setting new limits on the mixing angle theta_{13} with a large dataset and detailed background analysis.

Contribution

It provides the most stringent constraints to date on theta_{13} for various neutrino mass hierarchies using extensive MINOS data.

Findings

Observation of 54 candidate events with background of 49.1±7.0±2.7

Limits of 2sin^2(2θ_{13})sin^2(θ_{23})<0.12 (normal hierarchy)

Sets tightest limits on θ_{13} for most δ_{CP} values

Abstract

This letter reports results from a search for muon-neutrino to electron-neutrino transitions by the MINOS experiment based on a 7x10^20 protons-on-target exposure. Our observation of 54 candidate electron-neutrino events in the Far Detector with a background of 49.1+/-7.0(stat.)+/-2.7(syst.) events predicted by the measurements in the Near Detector requires 2sin^2(2theta_{13})sin^2(theta_{23})<0.12 (0.20) at the 90% C.L. for the normal (inverted) mass hierarchy at delta_cp=0. The experiment sets the tightest limits to date on the value of theta_{13} for nearly all values of delta_cp for the normal neutrino mass hierarchy and maximal sin^2(2theta_{23}).