Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam.

K Abe,M Kabirnezhad,D Barrow,S Dolan,T Ishii,T Matsubara,A Chappell,A Ereditato,M Tzanov,M Friend,Y Yamada,S Johnson,B Bourguille,M Antonova,C Vilela,T Kikawa,A Ariga,K Nakamura,S Manly,S Yen,C Metelko,G Collazuol,A Cudd,A Minamino,H Kim,B Quilain,A Longhin,A Khotjantsev,S Moriyama,M Tajima,C Alt,S King,E Kearns,A Rubbia,G Christodoulou,L Berns,R Wendell,V Paolone,M Guigue,L O’Sullivan,T Koga,G Vasseur,N Dokania,K Niewczas,J Zalipska,Y Takeuchi,A Konaka,L Munteanu,B Radics,A Bravar,M Shiozawa,V Matveev,M Barbi,A Mefodiev,Y Sonoda,M Ishitsuka,K Nishikawa,H Kubo,A Pritchard,J Kameda,Y Wang,S Murphy,H Sekiya,J Holeczek,J Kim,M Mezzetto,T Kobayashi,R Shah,M Ziembicki,S Berkman,F Di Lodovico,A Kostin,K Wood,J Nowak,S Zsoldos,N Yershov,A Suzuki,M Jakkapu,A Knox,D Cherdack,T Lindner,C Densham,M Buizza Avanzini,F Nova,P Novella,Y Koshio,T Kajita,M Hogan,P Hamacher-Baumann,V Berardi,Y Kataoka,A Bubak,T Towstego,L Eklund,Y Asada,M Yokoyama,T Feusels,D Sgalaberna,W Uno,T Kutter,D Wark,T Vladisavljevic,D Brailsford,A Hiramoto,D Karlen,R Akutsu,M Batkiewicz-Kwasniak,K Porwit,H Kakuno,T Okusawa,A Rychter,K Fusshoeller,E Rondio,F Bench,J Pasternak,T Nakadaira,J Dumarchez,N Mccauley,A Shaykina,N Kukita,S Bienstock,F Iacob,M Licciardi,S Mine,Z Vallari,E Radicioni,M Hartz,T Maruyama,M Yu,K Sakashita,M Pavin,C Riccio,T Radermacher,B Jamieson,A Gorin,K Okumura,E Mazzucato,T Tsukamoto,K Yamamoto,M Nakahata,M Mccarthy,F Shaker,P Dunne,G Fiorillo,C Wilkinson,A Zalewska,S Ban,C Pidcott,S Kuribayashi,K Kowalik,L Magaletti,Y Hayato,O Mineev,L Marti-Magro,M Kuze,T Hayashino,S Nakayama,P Paudyal,G Barr,C Touramanis,N Chikuma,D Coplowe,L Koch,C Andreopoulos,K Nakayoshi,A Shvartsman,M Lawe,C Checchia,L Labarga,A Shaikhiev,R Kurjata,M Zito,T Katori,M Laveder,M Malek,L Maret,M Tada,C Mcgrew,F Sánchez,R Fukuda,S Bhadra,K Gameil,K Iwamoto,L Pickering,K Scholberg,J Schwehr,L Ludovici,K Yasutome,A Knight,Y Nishimura,S Bolognesi,M Gonin,A Beloshapkin,C Pistillo,A Weber,C Barry,J Calcutt,X Li,T Odagawa,S Emery-Schrenk,S Valder,A Blondel,Y Kudenko,K Matsushita,T Campbell,T Golan,C Wret,Y Oyama,A Izmaylov,C Giganti,K Mavrokoridis,T Yano,Y Kato,Y Awataguchi,O Drapier,L Cook,Y Seiya,J Kisiel,T Lux,M Ikeda,D Vargas,M Khabibullin,G Yang,G Pintaudi,C Yanagisawa,C Nantais,Y Fujii,Y Uchida,Y Fukuda,C Bronner,M Scott,T Hasegawa,T Sekiguchi,C Jesús-Valls,Y Nagai,A Zykova,T Dealtry,S Suvorov,A Cervera,T Nakaya,V Palladino,S L Cartwright ,D Bravo-Berguño ,Toru Ishida ,N C Hastings ,Stefan Roth ,Miao Jiang ,S M Oser ,Mathieu Lamoureux ,C A Ruggles ,H M O’keeffe ,Tadashi Yoshida ,Atsushi Takeda ,L Molina-Bueno ,M Posiadała-Zezula ,S J Jenkins ,J F Martin ,S L Liu ,L F Thompson ,A Dąbrowska ,T Wąchała ,Xiaoxu Lu ,J T Haigh ,S P Kasetti ,J Walsh ,J C Nugent ,M B Smy ,John M Walker ,J L Palomino ,M G Catanesi ,Kendall Mahn ,William I Shorrock ,E T Atkin ,C K Jung ,G J Barker ,Daisuke Fukuda ,M R Vagins ,George Zarnecki ,A C Kaboth ,Tran Van Ngoc ,Б Popov ,E D Zimmerman ,R A Owen ,A Yu Smirnov ,N T Hong Van ,P Fernåndez ,E S Pinzon Guerra ,Ryuichi Fujita ,L L Kormos ,K S Mcfarland ,R P Litchfield ,J P Coleman ,Makoto Miura ,Satoshi Tanaka ,J Łagoda ,Ahmed Farag Ali ,P Jönsson ,A C Ruggeri ,D J Payne ,Yasuhiro Nakajima ,S R Dennis ,A A Sztuc ,Vadim Volkov ,C François ,P N Ratoff ,Tony Doyle ,E Reinherz‐Aronis ,T S Nonnenmacher ,A D Marino ,Jochen Steinmann ,Shuo Cao ,P F Denner ,J R Wilson ,L N Machado ,W H Toki ,Shigeki Aoki ,К Заремба ,Akihiko Nakamura ,Yoshihiro Suzuki ,R J Wilson ,S B Boyd ,A K Ichikawa ,J Sobczyk ,S Suzuki ,G C Penn ,G A Fiorentini ,T Mueller ,Yosuke Ashida ,M O Wascko ,G Rosa ,F J P Soler ,William C Parker ,W G S Vinning ,H A Tanaka ,L H V Anthony ,H Tanaka ,C M Schloesser ,M J Wilking ,A J Finch ,H W Sobel ,D R Hadley ,K M Tsui ,John H Morrison

doi:10.1103/physrevlett.124.161802

Abstract

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Highlights

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam
the hypothesis of no electron antineutrino appearance is disfavored with a significance
A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data

Summary

Muon Antineutrino Beam

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Published by the American Physical Society

The analysis presented here uses data collected from

Fraction of pseudoexperiments

Normal hierarchy Inverted hierarchy