Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target.

K Abe,L Maret,A Blondel,S Mine,T Lou,M Laveder,S Bienstock,K Iwamoto,T Radermacher,C Wilkinson,K Nakayoshi,M Tzanov,E Mazzucato,T Kobayashi,V Palladino,M Zito,J Dumarchez,Y Fujii,T Matsubara,R Tacik,C Riccio,G Fiorillo,P Paudyal,Y Seiya,M Mezzetto,C Nielsen,K Nishikawa,C Vilela,Y Koshio,T Maruyama,T Stewart,F Hosomi,C Touramanis,A Knight,V Paolone,B Bourguille,Y Yamada,M Kuze,D Cherdack,T Hasegawa,T Nakadaira,A Chappell,M Buizza Avanzini,K Nakamura,D Coplowe,M Khabibullin,L Koch,P Lasorak,M Smy,T Tsukamoto,A Hiramoto,X Li,V Berardi,M Yu,G Christodoulou,W Oryszczak,J Holeczek,Z Vallari,S Bhadra,D Brailsford,M Batkiewicz,D Shaw,J Kisiel,S Bolognesi,C Densham,C Mcgrew,L Labarga,K Scholberg,M Barbi,A Suzuki,T Dealtry,A Shaikhiev,W Uno,T Golan,A Ariga,N Chikuma,S Ban,A Minamino,G Collazuol,S King,R Akutsu,F Sánchez,J Schwehr,C Pistillo,G Yang,R Wendell,P Stowell,T Ishii,C Barry,M Shiozawa,M Friend,D Sgalaberna,A Zalewska,L O’Sullivan,Y Oyama,E Kearns,K Okumura,S Yamasu,A Cudd,L Magaletti,A Rubbia,J Nowak,C Metelko,E Scantamburlo,M Kabirnezhad,B Jamieson,M Hartz,S Manly,M Ikeda,N Yershov,J Imber,N Dokania,F Shaker,T Lindner,C Wret,T Sekiguchi,K Gameil,K Mavrokoridis,M Gonin,A Cervera,S Berkman,K Kowalik,A Konaka,P Dunne,K Yasutome,Y Fukuda,D Wark,Y Hayato,A Ereditato,E Radicioni,Y Nishimura,H Kim,D Hansen,G De Rosa,K Niewczas,T Campbell,S Cao,A Longhin,Y Azuma,S Murphy,A Missert,C Yanagisawa,S Emery-Schrenk,T Nakaya,K Yamamoto,R Shah,O Mineev,C Nantais,T Thakore,A Izmaylov,H Kakuno,J Kameda,S Yen,S Zsoldos,R Kurjata,B Quilain,P Hamacher-Baumann,L Berns,O Drapier,M Hogan,M Lawe,T Hayashino,L Ludovici,B Rossi,A Rychter,A Knox,T Yano,E Rondio,M Tada,G Vasseur,K Porwit,M Scott,M Licciardi,T Koga,A Mefodiev,T Kutter,J Calcutt,M Ishitsuka,C Andreopoulos,M Antonova,F Di Lodovico,Y Kato,M Ziembicki,F Bench,C Pidcott,S Nakayama,L Haegel,A Pritchard,Y Kudenko,M Mccarthy,M Yokoyama,N Mccauley,C Bronner,J Zalipska,Y Suda,D Karlen,A Zykova,Y Wang,M Pavin,Y Nagai,J Harada,G Barr,M Malek,K Sakashita,F Gizzarelli,S Moriyama,S Suvorov,S Johnson,A Weber,S Dolan,P Novella,T Feusels,T Okusawa,Y Takeuchi,A Khotjantsev,T Kajita,C Giganti,V Matveev,Y Sonoda,M Nakahata,T Vladisavljevic,H Kubo,J Kim,C Checchia,P Martins,Y Uchida,H Sekiya,T Katori,L Pickering,A Bravar,P Jönsson ,N C Hastings ,H W Sobel ,К Заремба ,G A Fiorentini ,M R Vagins ,E S Pinzon Guerra ,A K Ichikawa ,Toru Ishida ,George Zarnecki ,A D Marino ,A Dąbrowska ,P P Koller ,Z Liptak ,D J Payne ,A C Ruggeri ,Yoshihiro Suzuki ,A A Sztuc ,Makoto Miura ,Ryuichi Fujita ,W Y ,M G Catanesi ,J L Palomino ,P Fernández ,J P Coleman ,Jochen Steinmann ,G J Barker ,J P Lopez ,S B Boyd ,Shoji Suzuki ,D R Hadley ,K S Mcfarland ,John M Walker ,T S Nonnenmacher ,J T Sobczyk ,H M O’keeffe ,Kendall Mahn ,P N Ratoff ,M O Wascko ,Mathieu Lamoureux ,Б Popov ,Yasuhiro Nakajima ,Tadashi Yoshida ,A Yu Smirnov ,S R Dennis ,Yuta Nakanishi ,M Posiadała-Zezula ,R A Intonti ,Ahmed Farag Ali ,Shigeki Aoki ,A J Finch ,R M Berner ,Daisuke Fukuda ,L L Kormos ,S M Oser ,E Reinherz‐Aronis ,J T Haigh ,S L Cartwright ,J R Wilson ,Takashi Inoue ,Miao Jiang ,K M Tsui ,J F Martin ,C François ,Hirohisa Tanaka ,Stefan Roth ,L H V Anthony ,R P Litchfield ,Shin Sasaki ,Hidekazu Tanaka ,Vadim Volkov ,W H Toki ,L F Thompson ,J Łagoda ,P F Denner ,E D Zimmerman ,T Wąchała ,T Mueller ,X.-G Lu ,C K Jung ,A C Kaboth ,R A Owen ,Atsushi Takeda ,Yosuke Ashida ,K Duffy ,Ryo Tamura ,R J Wilson ,John H Morrison ,M J Wilking ,J L Amey

doi:10.1103/physrevlett.121.171802

Abstract

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3} eV^{2}/c^{4}.

Highlights

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2 × 1021 Protons on Target
CP symmetry can be violated in neutrino oscillations
The PMNS matrix is parametrized by three mixing angles