First Observation of Accelerator Muon Antineutrinos in MINOS

TL;DR

This paper reports the first direct detection of muon antineutrinos in the MINOS experiment, using magnetic charge separation to study their oscillation behavior and set limits on neutrino-antineutrino transformations.

Contribution

It presents the first observation of muon antineutrinos in MINOS and discusses future measurements with a dedicated antineutrino beam.

Findings

First direct detection of muon antineutrinos in MINOS

Preliminary results on antineutrino oscillation parameters

Limits on neutrino to antineutrino disappearance and reappearance

Abstract

We report the first direct observation of muon antineutrinos in the MINOS Far Detector in the current muon-neutrino dominated beam. The magnetic field of the detector is utilized to separate muon neutrinos and antineutrinos event-by-event by identifying the charge sign of the muon created in charged-current interactions. We present preliminary results on the muon antineutrino oscillation parameters as well as limit on the fraction of neutrinos that disappear and reappear as antineutrinos. We also discuss the prospect of the measurement when the polarity of the magnetic focusing horns will be reversed to create a dedicated muon antineutrino beam.