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

K Abe; R Akutsu; A Ali; J Amey; C Andreopoulos; L Anthony; M Antonova; S Aoki; A Ariga; Y Ashida; Y Azuma; S Ban; M Barbi; G J Barker; G Barr; C Barry; M Batkiewicz; F Bench; V Berardi; S Berkman; R M Berner; L Berns; S Bhadra; S Bienstock; A Blondel; S Bolognesi; B Bourguille; S B Boyd; D Brailsford; A Bravar; C Bronner; M Buizza Avanzini; J Calcutt; T Campbell; S Cao; S L Cartwright; M G Catanesi; A Cervera; A Chappell; C Checchia; D Cherdack; N Chikuma; G Christodoulou; J Coleman; G Collazuol; D Coplowe; A Cudd; A Dabrowska; G De Rosa; T Dealtry; P F Denner; S R Dennis; C Densham; F Di Lodovico; N Dokania; S Dolan; O Drapier; K E Duffy; J Dumarchez; P Dunne; S Emery-Schrenk; A Ereditato; P Fernandez; T Feusels; A J Finch; G A Fiorentini; G Fiorillo; C Francois; M Friend; Y Fujii; R Fujita; D Fukuda; Y Fukuda; K Gameil; C Giganti; F Gizzarelli; T Golan; M Gonin; D R Hadley; L Haegel; J T Haigh; P Hamacher-Baumann; D Hansen; J Harada; M Hartz; T Hasegawa; N C Hastings; T Hayashino; Y Hayato; A Hiramoto; M Hogan; J Holeczek; F Hosomi; A K Ichikawa; M Ikeda; J Imber; T Inoue; R A Intonti; T Ishida; T Ishii; M Ishitsuka; K Iwamoto; A Izmaylov; B Jamieson; M Jiang; S Johnson; P Jonsson; C K Jung; M Kabirnezhad; A C Kaboth; T Kajita; H Kakuno; J Kameda; D Karlen; T Katori; Y Kato; E Kearns; M Khabibullin; A Khotjantsev; H Kim; J Kim; S King; J Kisiel; A Knight; A Knox; T Kobayashi; L Koch; T Koga; P P Koller; A Konaka; L L Kormos; Y Koshio; K Kowalik; H Kubo; Y Kudenko; R Kurjata; T Kutter; M Kuze; L Labarga; J Lagoda; M Lamoureux; P Lasorak; M Laveder; M Lawe; M Licciardi; T Lindner; Z J Liptak; R P Litchfield; X Li; A Longhin; J P Lopez; T Lou; L Ludovici; X Lu; L Magaletti; K Mahn; M Malek; S Manly; L Maret; A D Marino; J F Martin; P Martins; T Maruyama; T Matsubara; V Matveev; K Mavrokoridis; W Y Ma; E Mazzucato; M McCarthy; N McCauley; K S McFarland; C McGrew; A Mefodiev; C Metelko; M Mezzetto; A Minamino; O Mineev; S Mine; A Missert; M Miura; S Moriyama; J Morrison; Th A Mueller; S Murphy; Y Nagai; T Nakadaira; M Nakahata; Y Nakajima; K G Nakamura; K Nakamura; K D Nakamura; Y Nakanishi; S Nakayama; T Nakaya; K Nakayoshi; C Nantais; C Nielsen; K Niewczas; K Nishikawa; Y Nishimura; T S Nonnenmacher; P Novella; J Nowak; H M O'Keeffe; L O'Sullivan; K Okumura; T Okusawa; W Oryszczak; S M Oser; R A Owen; Y Oyama; V Palladino; J L Palomino; V Paolone; P Paudyal; M Pavin; D Payne; L Pickering; C Pidcott; E S Pinzon Guerra; C Pistillo; B Popov; K Porwit; M Posiadala-Zezula; A Pritchard; B Quilain; T Radermacher; E Radicioni; P N Ratoff; E Reinherz-Aronis; C Riccio; E Rondio; B Rossi; S Roth; A Rubbia; A C Ruggeri; A Rychter; K Sakashita; F Sánchez; S Sasaki; E Scantamburlo; K Scholberg; J Schwehr; M Scott; Y Seiya; T Sekiguchi; H Sekiya; D Sgalaberna; R Shah; A Shaikhiev; F Shaker; D Shaw; M Shiozawa; A Smirnov; M Smy; J T Sobczyk; H Sobel; Y Sonoda; J Steinmann; T Stewart; P Stowell; Y Suda; S Suvorov; A Suzuki; S Y Suzuki; Y Suzuki; A A Sztuc; R Tacik; M Tada; A Takeda; Y Takeuchi; R Tamura; H K Tanaka; H A Tanaka; T Thakore; L F Thompson; W Toki; C Touramanis; K M Tsui; T Tsukamoto; M Tzanov; Y Uchida; W Uno; M Vagins; Z Vallari; G Vasseur; C Vilela; T Vladisavljevic; V V Volkov; T Wachala; J Walker; Y Wang; D Wark; M O Wascko; A Weber; R Wendell; M J Wilking; C Wilkinson; J R Wilson; R J Wilson; C Wret; Y Yamada; K Yamamoto; S Yamasu; C Yanagisawa; G Yang; T Yano; K Yasutome; S Yen; N Yershov; M Yokoyama; T Yoshida; M Yu; A Zalewska; J Zalipska; K Zaremba; G Zarnecki; M Ziembicki; E D Zimmerman; M Zito; S Zsoldos; A Zykova; T2K Collaboration

doi:10.1103/PhysRevLett.121.171802

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

Phys Rev Lett. 2018 Oct 26;121(17):171802. doi: 10.1103/PhysRevLett.121.171802.

Authors

K Abe¹, R Akutsu², A Ali³, J Amey⁴, C Andreopoulos^{5

6}, L Anthony⁵, M Antonova⁷, S Aoki⁸, A Ariga⁹, Y Ashida¹⁰, Y Azuma¹¹, S Ban¹⁰, M Barbi¹², G J Barker¹³, G Barr¹⁴, C Barry⁵, M Batkiewicz¹⁵, F Bench⁵, V Berardi¹⁶, S Berkman^{17

18}, R M Berner⁹, L Berns¹⁹, S Bhadra²⁰, S Bienstock²¹, A Blondel²², S Bolognesi²³, B Bourguille²⁴, S B Boyd¹³, D Brailsford²⁵, A Bravar²², C Bronner¹, M Buizza Avanzini²⁶, J Calcutt²⁷, T Campbell²⁸, S Cao²⁹, S L Cartwright³⁰, M G Catanesi¹⁶, A Cervera⁷, A Chappell¹³, C Checchia³, D Cherdack²⁸, N Chikuma³¹, G Christodoulou⁵, J Coleman⁵, G Collazuol³, D Coplowe¹⁴, A Cudd²⁷, A Dabrowska¹⁵, G De Rosa³², T Dealtry²⁵, P F Denner¹³, S R Dennis⁵, C Densham⁶, F Di Lodovico³³, N Dokania³⁴, S Dolan^{23

26}, O Drapier²⁶, K E Duffy¹⁴, J Dumarchez²¹, P Dunne⁴, S Emery-Schrenk²³, A Ereditato⁹, P Fernandez⁷, T Feusels^{17

18}, A J Finch²⁵, G A Fiorentini²⁰, G Fiorillo³², C Francois⁹, M Friend²⁹, Y Fujii²⁹, R Fujita³¹, D Fukuda³⁵, Y Fukuda³⁶, K Gameil^{17

18}, C Giganti²¹, F Gizzarelli²³, T Golan³⁷, M Gonin²⁶, D R Hadley¹³, L Haegel²², J T Haigh¹³, P Hamacher-Baumann³⁸, D Hansen³⁹, J Harada¹¹, M Hartz^{40

18}, T Hasegawa²⁹, N C Hastings¹², T Hayashino¹⁰, Y Hayato^{40

1}, A Hiramoto¹⁰, M Hogan²⁸, J Holeczek⁴¹, F Hosomi³¹, A K Ichikawa¹⁰, M Ikeda¹, J Imber²⁶, T Inoue¹¹, R A Intonti¹⁶, T Ishida²⁹, T Ishii²⁹, M Ishitsuka⁴², K Iwamoto³¹, A Izmaylov^{7

43}, B Jamieson⁴⁴, M Jiang¹⁰, S Johnson⁴⁵, P Jonsson⁴, C K Jung³⁴, M Kabirnezhad¹⁴, A C Kaboth^{46

6}, T Kajita², H Kakuno⁴⁷, J Kameda¹, D Karlen^{18

48}, T Katori³³, Y Kato¹, E Kearns^{49

40}, M Khabibullin⁴³, A Khotjantsev⁴³, H Kim¹¹, J Kim^{17

18}, S King³³, J Kisiel⁴¹, A Knight¹³, A Knox²⁵, T Kobayashi²⁹, L Koch⁶, T Koga³¹, P P Koller⁹, A Konaka¹⁸, L L Kormos²⁵, Y Koshio³⁵, K Kowalik⁵⁰, H Kubo¹⁰, Y Kudenko⁴³, R Kurjata⁵¹, T Kutter⁵², M Kuze¹⁹, L Labarga⁵³, J Lagoda⁵⁰, M Lamoureux²³, P Lasorak³³, M Laveder³, M Lawe²⁵, M Licciardi²⁶, T Lindner¹⁸, Z J Liptak⁴⁵, R P Litchfield⁴, X Li³⁴, A Longhin³, J P Lopez⁴⁵, T Lou³¹, L Ludovici⁵⁴, X Lu¹⁴, L Magaletti¹⁶, K Mahn²⁷, M Malek³⁰, S Manly⁵⁵, L Maret²², A D Marino⁴⁵, J F Martin⁵⁶, P Martins³³, T Maruyama²⁹, T Matsubara²⁹, V Matveev⁴³, K Mavrokoridis⁵, W Y Ma⁴, E Mazzucato²³, M McCarthy²⁰, N McCauley⁵, K S McFarland⁵⁵, C McGrew³⁴, A Mefodiev⁴³, C Metelko⁵, M Mezzetto³, A Minamino⁵⁷, O Mineev⁴³, S Mine⁵⁸, A Missert⁴⁵, M Miura¹, S Moriyama¹, J Morrison²⁷, Th A Mueller²⁶, S Murphy⁵⁹, Y Nagai⁴⁵, T Nakadaira²⁹, M Nakahata^{40

1}, Y Nakajima¹, K G Nakamura¹⁰, K Nakamura^{29

40}, K D Nakamura¹⁰, Y Nakanishi¹⁰, S Nakayama¹, T Nakaya^{40

10}, K Nakayoshi²⁹, C Nantais⁵⁶, C Nielsen^{17

18}, K Niewczas³⁷, K Nishikawa²⁹, Y Nishimura², T S Nonnenmacher⁴, P Novella⁷, J Nowak²⁵, H M O'Keeffe²⁵, L O'Sullivan³⁰, K Okumura^{40

2}, T Okusawa¹¹, W Oryszczak⁶⁰, S M Oser^{17

18}, R A Owen³³, Y Oyama²⁹, V Palladino³², J L Palomino³⁴, V Paolone³⁹, P Paudyal⁵, M Pavin¹⁸, D Payne⁵, L Pickering²⁷, C Pidcott³⁰, E S Pinzon Guerra²⁰, C Pistillo⁹, B Popov²¹, K Porwit⁴¹, M Posiadala-Zezula⁶⁰, A Pritchard⁵, B Quilain⁴⁰, T Radermacher³⁸, E Radicioni¹⁶, P N Ratoff²⁵, E Reinherz-Aronis²⁸, C Riccio³², E Rondio⁵⁰, B Rossi³², S Roth³⁸, A Rubbia⁵⁹, A C Ruggeri³², A Rychter⁵¹, K Sakashita²⁹, F Sánchez²², S Sasaki⁴⁷, E Scantamburlo²², K Scholberg⁶¹, J Schwehr²⁸, M Scott⁴, Y Seiya¹¹, T Sekiguchi²⁹, H Sekiya^{40

1}, D Sgalaberna²², R Shah^{14

6}, A Shaikhiev⁴³, F Shaker⁴⁴, D Shaw²⁵, M Shiozawa^{40

1}, A Smirnov⁴³, M Smy⁵⁸, J T Sobczyk³⁷, H Sobel^{58

40}, Y Sonoda¹, J Steinmann³⁸, T Stewart⁶, P Stowell³⁰, Y Suda³¹, S Suvorov^{23

43}, A Suzuki⁸, S Y Suzuki²⁹, Y Suzuki⁴⁰, A A Sztuc⁴, R Tacik^{12

18}, M Tada²⁹, A Takeda¹, Y Takeuchi^{40

8}, R Tamura³¹, H K Tanaka¹, H A Tanaka^{62

56}, T Thakore⁵², L F Thompson³⁰, W Toki²⁸, C Touramanis⁵, K M Tsui², T Tsukamoto²⁹, M Tzanov⁵², Y Uchida⁴, W Uno¹⁰, M Vagins^{58

40}, Z Vallari³⁴, G Vasseur²³, C Vilela³⁴, T Vladisavljevic^{40

14}, V V Volkov⁴³, T Wachala¹⁵, J Walker⁴⁴, Y Wang³⁴, D Wark^{14

6}, M O Wascko⁴, A Weber^{14

6}, R Wendell¹⁰, M J Wilking³⁴, C Wilkinson⁹, J R Wilson³³, R J Wilson²⁸, C Wret⁵⁵, Y Yamada²⁹, K Yamamoto¹¹, S Yamasu³⁵, C Yanagisawa³⁴, G Yang³⁴, T Yano¹, K Yasutome¹⁰, S Yen¹⁸, N Yershov⁴³, M Yokoyama³¹, T Yoshida¹⁹, M Yu²⁰, A Zalewska¹⁵, J Zalipska⁵⁰, K Zaremba⁵¹, G Zarnecki⁵⁰, M Ziembicki⁵¹, E D Zimmerman⁴⁵, M Zito²³, S Zsoldos³³, A Zykova⁴³; T2K Collaboration

Affiliations

¹ University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan.
² University of Tokyo, Institute for Cosmic Ray Research, Research Center for Cosmic Neutrinos, Kashiwa, Japan.
³ INFN Sezione di Padova and Università di Padova, Dipartimento di Fisica, Padova, Italy.
⁴ Imperial College London, Department of Physics, London, United Kingdom.
⁵ University of Liverpool, Department of Physics, Liverpool, United Kingdom.
⁶ STFC, Rutherford Appleton Laboratory, Harwell Oxford, and Daresbury Laboratory, Warrington, United Kingdom.
⁷ IFIC (CSIC and University of Valencia), Valencia, Spain.
⁸ Kobe University, Kobe, Japan.
⁹ University of Bern, Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), Bern, Switzerland.
¹⁰ Kyoto University, Department of Physics, Kyoto, Japan.
¹¹ Osaka City University, Department of Physics, Osaka, Japan.
¹² University of Regina, Department of Physics, Regina, Saskatchewan, Canada.
¹³ University of Warwick, Department of Physics, Coventry, United Kingdom.
¹⁴ Oxford University, Department of Physics, Oxford, United Kingdom.
¹⁵ H. Niewodniczanski Institute of Nuclear Physics PAN, Cracow, Poland.
¹⁶ INFN Sezione di Bari and Università e Politecnico di Bari, Dipartimento Interuniversitario di Fisica, Bari, Italy.
¹⁷ University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia, Canada.
¹⁸ TRIUMF, Vancouver, British Columbia, Canada.
¹⁹ Tokyo Institute of Technology, Department of Physics, Tokyo, Japan.
²⁰ York University, Department of Physics and Astronomy, Toronto, Ontario, Canada.
²¹ UPMC, Université Paris Diderot, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Paris, France.
²² University of Geneva, Section de Physique, DPNC, Geneva, Switzerland.
²³ IRFU, CEA Saclay, Gif-sur-Yvette, France.
²⁴ Institut de Fisica d'Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra (Barcelona), Spain.
²⁵ Lancaster University, Physics Department, Lancaster, United Kingdom.
²⁶ Ecole Polytechnique, IN2P3-CNRS, Laboratoire Leprince-Ringuet, Palaiseau, France.
²⁷ Michigan State University, Department of Physics and Astronomy, East Lansing, Michigan, USA.
²⁸ Colorado State University, Department of Physics, Fort Collins, Colorado, USA.
²⁹ High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan.
³⁰ University of Sheffield, Department of Physics and Astronomy, Sheffield, United Kingdom.
³¹ University of Tokyo, Department of Physics, Tokyo, Japan.
³² INFN Sezione di Napoli and Università di Napoli, Dipartimento di Fisica, Napoli, Italy.
³³ Queen Mary University of London, School of Physics and Astronomy, London, United Kingdom.
³⁴ State University of New York at Stony Brook, Department of Physics and Astronomy, Stony Brook, New York, USA.
³⁵ Okayama University, Department of Physics, Okayama, Japan.
³⁶ Miyagi University of Education, Department of Physics, Sendai, Japan.
³⁷ Wroclaw University, Faculty of Physics and Astronomy, Wroclaw, Poland.
³⁸ RWTH Aachen University, III. Physikalisches Institut, Aachen, Germany.
³⁹ University of Pittsburgh, Department of Physics and Astronomy, Pittsburgh, Pennsylvania, USA.
⁴⁰ Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan.
⁴¹ University of Silesia, Institute of Physics, Katowice, Poland.
⁴² Tokyo University of Science, Faculty of Science and Technology, Department of Physics, Noda, Chiba, Japan.
⁴³ Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia.
⁴⁴ University of Winnipeg, Department of Physics, Winnipeg, Manitoba, Canada.
⁴⁵ University of Colorado at Boulder, Department of Physics, Boulder, Colorado, USA.
⁴⁶ Royal Holloway University of London, Department of Physics, Egham, Surrey, United Kingdom.
⁴⁷ Tokyo Metropolitan University, Department of Physics, Tokyo, Japan.
⁴⁸ University of Victoria, Department of Physics and Astronomy, Victoria, British Columbia, Canada.
⁴⁹ Boston University, Department of Physics, Boston, Massachusetts, USA.
⁵⁰ National Centre for Nuclear Research, Warsaw, Poland.
⁵¹ Warsaw University of Technology, Institute of Radioelectronics, Warsaw, Poland.
⁵² Louisiana State University, Department of Physics and Astronomy, Baton Rouge, Louisiana, USA.
⁵³ University Autonoma Madrid, Department of Theoretical Physics, Madrid, Spain.
⁵⁴ INFN Sezione di Roma and Università di Roma "La Sapienza," Roma, Italy.
⁵⁵ University of Rochester, Department of Physics and Astronomy, Rochester, New York, USA.
⁵⁶ University of Toronto, Department of Physics, Toronto, Ontario, Canada.
⁵⁷ Yokohama National University, Faculty of Engineering, Yokohama, Japan.
⁵⁸ University of California, Irvine, Department of Physics and Astronomy, Irvine, California, USA.
⁵⁹ ETH Zurich, Institute for Particle Physics, Zurich, Switzerland.
⁶⁰ University of Warsaw, Faculty of Physics, Warsaw, Poland.
⁶¹ Duke University, Department of Physics, Durham, North Carolina, USA.
⁶² SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA.

PMID: 30411920
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}.