New Results from the MINOS Experiment - EPS 2011 conference proceedings

TL;DR

The MINOS experiment has provided new constraints on neutrino oscillation parameters, particularly setting upper limits on the mixing angle θ13 using long-baseline neutrino data collected since 2005.

Contribution

This paper reports the latest results from MINOS on neutrino oscillations, emphasizing electron neutrino appearance and constraints on the mixing angle θ13.

Findings

Upper limit of sin^2(2θ13) < 0.12 for normal hierarchy

Upper limit of sin^2(2θ13) < 0.20 for inverted hierarchy

Data collected corresponds to 8.2×10^{20} protons on target

Abstract

The MINOS experiment is a long-baseline neutrino experiment designed to study neutrino behaviour, in particular the phenomenon of neutrino oscillations. MINOS sends the NuMI neutrino beam through two detectors, a Near Detector 1 km downstream from the beam source at Fermilab, and a Far Detector 735 km away in the Soudan Mine in Minnesota. MINOS has been taking beam data since 2005. This document summarises recent neutrino oscillations results, with particular emphasis on electron neutrino appearance, which probes the angle $\theta_{13}$ of the neutrino mass mixing matrix. For an exposure of 8.2$\times 10^{20}$ protons on target, MINOS finds that $\sin^{2}(2\theta_{13})<0.12$ for the normal mass hierarchy, and $<0.20$ for the inverted mass hierarchy at the 90% C.L., if the CP-violating phase $\delta=0$.