First muon-neutrino disappearance study with an off-axis beam

Abe, K. and Abgrall, N. and Ajima, Y. and Aihara, H. and Albert, J. B. and Andreopoulos, C. and Andrieu, B. and Anerella, M. D. and Aoki, S. and Araoka, O. and Argyriades, J. and Ariga, A. and Ariga, T. and Assylbekov, S. and Autiero, D. and Badertscher, A. and Barbi, M. and Barker, G. J. and Barr, G. and Bass, M. and Batkiewicz, M. and Bay, F. and Bentham, S. and Berardi, V. and Berger, B. E. and Bertram, I. and Besnier, M. and Beucher, J. and Beznosko, D. and Bhadra, S. and Blaszczyk, F. d. M. and Blocki, J. and Blondel, A. and Bojechko, C. and Bouchez, J. and Boyd, S. B. and Bravar, A. and Bronner, C. and Brook-Roberge, D. G. and Buchanan, N. and Budd, H. and Calland, R. and Davies, G. S. and Finch, A. J. and Grant, N. and Hatzikoutelis, A. and Kormos, L. L. and Lawe, M. and Nowak, J. A. and Ratoff, P. N. (2012) First muon-neutrino disappearance study with an off-axis beam. Physical Review D, 85 (3). ISSN 1550-7998

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We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 x 10(20) protons on target, we observe 31 fully-contained single mu-like ring events in Super-Kamiokande, compared with an expectation of 104 +/- 14 (syst) events without neutrino oscillations. The best-fit point for two-flavor nu(mu) -> nu(tau) oscillations is sin(2)(2 theta(23)) = 0.98 and vertical bar Delta m(32)(2)vertical bar = 2.65 x 10(-3) eV(2). The boundary of the 90% confidence region includes the points sin(2)(2 theta(23)), vertical bar Delta m(32)(2)vertical bar = (1.0, 3.1 x 10(-3) eV(2)), (0.84, 2.65 x 10(-3) eV(2)) and (1.0, 2.2 x 10(-3) eV(2)).

Item Type:
Journal Article
Journal or Publication Title:
Physical Review D
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© 2012 American Physical Society
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Deposited On:
01 May 2013 08:52
Last Modified:
05 Jul 2020 03:41