Indication of Electron Neutrino Appearance from an Accelerator-produced
Off-axis Muon Neutrino Beam
ArXiv 1106.2822 (2011)
Authors:
T2K Collaboration, K Abe, N Abgrall, Y Ajima, H Aihara, JB Albert, C Andreopoulos, B Andrieu, S Aoki, O Araoka, J Argyriades, A Ariga, T Ariga, S Assylbekov, D Autiero, A Badertscher, M Barbi, GJ Barker, G Barr, M Bass, F Bay, S Bentham, V Berardi, BE Berger, I Bertram, M Besnier, J Beucher, D Beznosko, S Bhadra, FDM Blaszczyk, A Blondel, C Bojechko, J Bouchez, SB Boyd, A Bravar, C Bronner, DG Brook-Roberge, N Buchanan, H Budd, D Calvet, SL Cartwright, A Carver, R Castillo, MG Catanesi, A Cazes, A Cervera, C Chavez, S Choi, G Christodoulou, J Coleman, W Coleman, G Collazuol, K Connolly, A Curioni, A Dabrowska, I Danko, R Das, GS Davies, S Davis, M Day, G DeRosa, JPAM de Andre, P dePerio, A Delbart, C Densham, F DiLodovico, S DiLuise, P Dinh Tran, J Dobson, U Dore, O Drapier, F Dufour, J Dumarchez, S Dytman, M Dziewiecki, M Dziomba, S Emery, A Ereditato, L Escudero, LS Esposito, M Fechner, A Ferrero, AJ Finch, E Frank, Y Fujii, Y Fukuda, V Galymov, FC Gannaway, A Gaudin, A Gendotti, M George, S Giffin, C Giganti, K Gilje, T Golan, M Goldhaber, JJ Gomez-Cadenas, M Gonin, N Grant, A Grant, P Gumplinger, P Guzowski, A Haesler, MD Haigh, K Hamano, C Hansen, D Hansen, T Hara, PF Harrison, B Hartfiel, M Hartz, T Haruyama, T Hasegawa, NC Hastings, S Hastings, A Hatzikoutelis, K Hayashi, Y Hayato, C Hearty, RL Helmer, R Henderson, N Higashi, J Hignight, E Hirose, J Holeczek, S Horikawa, A Hyndman, AK Ichikawa, K Ieki, M Ieva, M Iida, M Ikeda, J Ilic, J Imber, T Ishida, C Ishihara, T Ishii, SJ Ives, M Iwasaki, K Iyogi, A Izmaylov, B Jamieson, RA Johnson, KK Joo, GV Jover-Manas, CK Jung, H Kaji, T Kajita, H Kakuno, J Kameda, K Kaneyuki, D Karlen, K Kasami, I Kato, E Kearns, M Khabibullin, F Khanam, A Khotjantsev, D Kielczewska, T Kikawa, J Kim, JY Kim, SB Kim, N Kimura, B Kirby, J Kisiel, P Kitching, T Kobayashi, G Kogan, S Koike, A Konaka, LL Kormos, A Korzenev, K Koseki, Y Koshio, Y Kouzuma, K Kowalik, V Kravtsov, I Kreslo, W Kropp, H Kubo, Y Kudenko, N Kulkarni, R Kurjata, T Kutter, J Lagoda, K Laihem, M Laveder, KP Lee, PT Le, JM Levy, C Licciardi, IT Lim, T Lindner, RP Litchfield, M Litos, A Longhin, GD Lopez, PF Loverre, L Ludovici, T Lux, M Macaire, K Mahn, Y Makida, M Malek, S Manly, A Marchionni, AD Marino, J Marteau, JF Martin, T Maruyama, T Maryon, J Marzec, P Masliah, EL Mathie, C Matsumura, K Matsuoka, V Matveev, K Mavrokoridis, E Mazzucato, N McCauley, KS McFarland, C McGrew, T McLachlan, M Messina, W Metcalf, C Metelko, M Mezzetto, P Mijakowski, CA Miller, A Minamino, O Mineev, S Mine, AD Missert, G Mituka, M Miura, K Mizouchi, L Monfregola, F Moreau, B Morgan, S Moriyama, A Muir, A Murakami, M Murdoch, S Murphy, J Myslik, T Nakadaira, M Nakahata, T Nakai, K Nakajima, T Nakamoto, K Nakamura, S Nakayama, T Nakaya, D Naples, ML Navin, B Nelson, TC Nicholls, K Nishikawa, H Nishino, JA Nowak, M Noy, Y Obayashi, T Ogitsu, H Ohhata, T Okamura, K Okumura, T Okusawa, SM Oser, M Otani, RA Owen, Y Oyama, T Ozaki, MY Pac, V Palladino, V Paolone, P Paul, D Payne, GF Pearce, JD Perkin, V Pettinacci, F Pierre, E Poplawska, B Popov, M Posiadala, J-M Poutissou, R Poutissou, P Przewlocki, W Qian, JL Raaf, E Radicioni, PN Ratoff, TM Raufer, M Ravonel, M Raymond, F Retiere, A Robert, PA Rodrigues, E Rondio, JM Roney, B Rossi, S Roth, A Rubbia, D Ruterbories, S Sabouri, R Sacco, K Sakashita, F Sanchez, A Sarrat, K Sasaki, K Scholberg, J Schwehr, M Scott, DI Scully, Y Seiya, T Sekiguchi, H Sekiya, M Shibata, Y Shimizu, M Shiozawa, S Short, M Syiad, RJ Smith, M Smy, JT Sobczyk, H Sobel, M Sorel, A Stahl, P Stamoulis, J Steinmann, B Still, J Stone, C Strabel, LR Sulak, R Sulej, P Sutcliffe, A Suzuki, K Suzuki, S Suzuki, SY Suzuki, Y Suzuki, Y Suzuki, T Szeglowski, M Szeptycka, R Tacik, M Tada, S Takahashi, A Takeda, Y Takenaga, Y Takeuchi, K Tanaka, HA Tanaka, M Tanaka, MM Tanaka, N Tanimoto, K Tashiro, I Taylor, A Terashima, D Terhorst, R Terri, LF Thompson, A Thorley, W Toki, T Tomaru, Y Totsuka, C Touramanis, T Tsukamoto, M Tzanov, Y Uchida, K Ueno, A Vacheret, M Vagins, G Vasseur, T Wachala, JJ Walding, AV Waldron, CW Walter, PJ Wanderer, J Wang, MA Ward, GP Ward, D Wark, MO Wascko, A Weber, R Wendell, N West, LH Whitehead, G Wikstrom, RJ Wilkes, MJ Wilking, JR Wilson, RJ Wilson, T Wongjirad, S Yamada, Y Yamada, A Yamamoto, K Yamamoto, Y Yamanoi, H Yamaoka, C Yanagisawa, T Yano, S Yen, N Yershov, M Yokoyama, A Zalewska, J Zalipska, L Zambelli, K Zaremba, M Ziembicki, ED Zimmerman, M Zito, J Zmuda
Abstract:
The T2K experiment observes indications of $\nu_\mu\rightarrow \nu_e$
appearance in data accumulated with $1.43\times10^{20}$ protons on target. Six
events pass all selection criteria at the far detector. In a three-flavor
neutrino oscillation scenario with $|\Delta m_{23}^2|=2.4\times10^{-3}$ eV$^2$,
$\sin^2 2\theta_{23}=1$ and $\sin^2 2\theta_{13}=0$, the expected number of
such events is 1.5$\pm$0.3(syst.). Under this hypothesis, the probability to
observe six or more candidate events is 7$\times10^{-3}$, equivalent to
2.5$\sigma$ significance. At 90% C.L., the data are consistent with
0.03(0.04)$<\sin^2 2\theta_{13}<$ 0.28(0.34) for $\delta_{\rm CP}=0$ and a
normal (inverted) hierarchy.
