Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment

Phys Rev Lett. 2008 Nov 28;101(22):221804. doi: 10.1103/PhysRevLett.101.221804. Epub 2008 Nov 26.

Abstract

We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.