51. First direct observation of muon antineutrino disappearance.
- Author
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Adamson P, Andreopoulos C, Auty DJ, Ayres DS, Backhouse C, Barr G, Bishai M, Blake A, Bock GJ, Boehnlein DJ, Bogert D, Cavanaugh S, Cherdack D, Childress S, Choudhary BC, Coelho JA, Coleman SJ, Corwin L, Cronin-Hennessy D, Danko IZ, de Jong JK, Devenish NE, Diwan MV, Dorman M, Escobar CO, Evans JJ, Falk E, Feldman GJ, Frohne MV, Gallagher HR, Gomes RA, Goodman MC, Gouffon P, Graf N, Gran R, Grant N, Grzelak K, Habig A, Harris D, Hartnell J, Hatcher R, Himmel A, Holin A, Howcroft C, Huang X, Hylen J, Ilic J, Irwin GM, Isvan Z, Jaffe DE, James C, Jensen D, Kafka T, Kasahara SM, Koizumi G, Kopp S, Kordosky M, Kreymer A, Lang K, Lefeuvre G, Ling J, Litchfield PJ, Loiacono L, Lucas P, Mann WA, Marshak ML, Mayer N, McGowan AM, Mehdiyev R, Meier JR, Messier MD, Miller WH, Mishra SR, Mitchell J, Moore CD, Morfín J, Mualem L, Mufson S, Musser J, Naples D, Nelson JK, Newman HB, Nichol RJ, Nicholls TC, Nowak JA, Ochoa-Ricoux JP, Oliver WP, Orchanian M, Ospanov R, Paley J, Patterson RB, Pawloski G, Pearce GF, Petyt DA, Phan-Budd S, Plunkett RK, Qiu X, Ratchford J, Raufer TM, Rebel B, Rodrigues PA, Rosenfeld C, Rubin HA, Sanchez MC, Schneps J, Schreiner P, Shanahan P, Sousa A, Stamoulis P, Strait M, Tagg N, Talaga RL, Tetteh-Lartey E, Thomas J, Thomson MA, Tinti G, Toner R, Tzanakos G, Urheim J, Vahle P, Viren B, Weber A, Webb RC, White C, Whitehead L, Wojcicki SG, Yang T, and Zwaska R
- Abstract
This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(μ) production, accumulating an exposure of 1.71 × 10²⁰ protons on target. In the Far Detector, 97 charged current ν(μ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm²| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10⁻³ eV², sin²(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(μ) and ν(μ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.
- Published
- 2011
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