First direct observation of Muon antineutrino disappearance

P. Adamson, C. Andreopoulos, D. J. Auty, D. S. Ayres, C. Backhouse, G. Barr, M. Bishai, A. Blake, G. J. Bock, D. J. Boehnlein, D. Bogert, S. Cavanaugh, D. Cherdack, S. Childress, B. C. Choudhary, J. A.B. Coelho, S. J. Coleman, L. Corwin, D. Cronin-Hennessy, I. Z. DankoJ. K. De Jong, N. E. Devenish, M. V. Diwan, M. Dorman, C. O. Escobar, J. J. Evans, E. Falk, G. J. Feldman, M. V. Frohne, H. R. Gallagher, R. A. Gomes, M. C. Goodman, P. Gouffon, N. Graf, R. Gran, N. Grant, K. Grzelak, A. Habig, D. Harris, J. Hartnell, R. Hatcher, A. Himmel, A. Holin, C. Howcroft, X. Huang, J. Hylen, J. Ilic, G. M. Irwin, Z. Isvan, D. E. Jaffe

Research output: Contribution to journalArticlepeer-review

78 Scopus citations


This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν̄μ production, accumulating an exposure of 1.71×1020 protons on target. In the Far Detector, 97 charged current ν̄μ events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm⊃̄2|=[3.36-0.40+0.46(stat)±0.06(syst)] ×10⊃-3eV2, ⊃sin⊃2(2θ̄)=0.86-0.12+0.11(stat) ±0.01(syst). The MINOS νμ and ν̄μ measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

Original languageEnglish (US)
Article number021801
JournalPhysical review letters
Issue number2
StatePublished - Jul 5 2011


Dive into the research topics of 'First direct observation of Muon antineutrino disappearance'. Together they form a unique fingerprint.

Cite this