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arXiv · 1201.1386

First Muon-Neutrino Disappearance Study with an Off-Axis Beam

T2K Collaboration·K. Abe·N. Abgrall·Y. Ajima·H. Aihara·J. B. Albert·C. Andreopoulos·B. Andrieu·M. D. Anerella·S. Aoki·O. Araoka·J. Argyriades·A. Ariga·T. Ariga·S. Assylbekov·D. Autiero·A. Badertscher·M. Barbi·G. J. Barker·G. Barr·M. Bass·M. Batkiewicz·F. Bay·S. Bentham·V. Berardi·B. E. Berger·I. Bertram·M. Besnier·J. Beucher·D. Beznosko·S. Bhadra·F. d. M. Blaszczyk·J. Blocki·A. Blondel·C. Bojechko·J. Bouchez·S. B. Boyd·A. Bravar·C. Bronner·D. G. Brook-Roberge·N. Buchanan·H. Budd·R. Calland·D. Calvet·J. Caravaca Rodriguez·S. L. Cartwright·A. Carver·R. Castillo·M. G. Catanesi·A. Cazes·A. Cervera·C. Chavez·S. Choi·G. Christodoulou·J. Coleman·G. Collazuol·W. Coleman·K. Connolly·A. Curioni·A. Dabrowska·I. Danko·R. Das·G. S. Davies·S. Davis·M. Day·G. De Rosa·J. P. A. M. de André·P. de Perio·T. Dealtry·A. Delbart·C. Densham·F. Di Lodovico·S. Di Luise·P. Dinh Tran·J. Dobson·U. Dore·O. Drapier·T. Duboyski·F. Dufour·J. Dumarchez·S. Dytman·M. Dziewiecki·M. Dziomba·S. Emery·A. Ereditato·J. E. Escallier·L. Escudero·L. S. Esposito·M. Fechner·A. Ferrero·A. J. Finch·E. Frank·Y. Fujii·Y. Fukuda·V. Galymov·G. L. Ganetis·F. C. Gannaway·A. Gaudin·A. Gendotti·M. A. George
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Abstract

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 10**20 protons on target, we observe 31 fully-contained single muon-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 |\Delta m**2_32| = 2.65 10**-3 eV**2. The boundary of the 90 % confidence region includes the points (sin**2(2 theta_23),|\Delta m**2_32|) = (1.0, 3.1 10**-3 eV**2), (0.84, 2.65 10**-3 eV**2) and (1.0, 2.2 10**-3 eV**2).

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T2K Collaboration, K. Abe, N. Abgrall, Y. Ajima, H. Aihara, J. B. Albert, C. Andreopoulos, B. Andrieu, M. D. Anerella, S. Aoki, O. Araoka, J. Argyriades, A. Ariga, T. Ariga, S. Assylbekov, D. Autiero, A. Badertscher, M. Barbi, G. J. Barker, G. Barr, M. Bass, M. Batkiewicz, F. Bay, S. Bentham, V. Berardi, B. E. Berger, I. Bertram, M. Besnier, J. Beucher, D. Beznosko, S. Bhadra, F. d. M. Blaszczyk, J. Blocki, A. Blondel, C. Bojechko, J. Bouchez, S. B. Boyd, A. Bravar, C. Bronner, D. G. Brook-Roberge, N. Buchanan, H. Budd, R. Calland, D. Calvet, J. Caravaca Rodriguez, S. L. Cartwright, A. Carver, R. Castillo, M. G. Catanesi, A. Cazes, A. Cervera, C. Chavez, S. Choi, G. Christodoulou, J. Coleman, G. Collazuol, W. Coleman, K. Connolly, A. Curioni, A. Dabrowska, I. Danko, R. Das, G. S. Davies, S. Davis, M. Day, G. De Rosa, J. P. A. M. de André, P. de Perio, T. Dealtry, A. Delbart, C. Densham, F. Di Lodovico, S. Di Luise, P. Dinh Tran, J. Dobson, U. Dore, O. Drapier, T. Duboyski, F. Dufour, J. Dumarchez, S. Dytman, M. Dziewiecki, M. Dziomba, S. Emery, A. Ereditato, J. E. Escallier, L. Escudero, L. S. Esposito, M. Fechner, A. Ferrero, A. J. Finch, E. Frank, Y. Fujii, Y. Fukuda, V. Galymov, G. L. Ganetis, F. C. Gannaway, A. Gaudin, A. Gendotti, M. A. George. 2012-01-06. First Muon-Neutrino Disappearance Study with an Off-Axis Beam. https://doi.org/10.1103/physrevd.85.031103

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