Title
First Direct Observation of Muon Antineutrino Disappearance
Document Type
Article
Department/Program
Physics
Journal Title
Physical Review Letters
Pub Date
2011
Volume
107
Issue
1
Abstract
This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for (nu) over bar (mu) production, accumulating an exposure of 1.71 x 10(20) protons on target. In the Far Detector, 97 charged current (nu) over bar (mu) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3 sigma. The best fit to oscillation yields vertical bar Delta(m) over bar (2)vertical bar = [3.36(-0.40)(+0.46)(stat) +/- 0.06(sys)] x 10(-3) eV(2), sin(2)(2 (theta) over bar) = 0.86(-0.12)(+0.11)(stat) +/- 0.01(syst). The MINOS nu(mu) and (nu) over bar (mu) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.
Recommended Citation
Adamson, P.; Bock, G. J.; Boehnlein, D. J.; Coleman, S. J.; Kordosky, M.; Nelson, J. K.; and Vahle, P., First Direct Observation of Muon Antineutrino Disappearance (2011). Physical Review Letters, 107(1).
10.1103/PhysRevLett.107.021801
DOI
10.1103/PhysRevLett.107.021801