Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam

K Abe; J Adam; H Aihara; T Akiri; C Andreopoulos; S Aoki; A Ariga; T Ariga; S Assylbekov; D Autiero; M Barbi; G J Barker; G Barr; M Bass; M Batkiewicz; F Bay; S W Bentham; V Berardi; B E Berger; S Berkman; I Bertram; S Bhadra; F d M Blaszczyk; A Blondel; C Bojechko; S Bordoni; S B Boyd; D Brailsford; A Bravar; C Bronner; N Buchanan; R G Calland; J Caravaca Rodríguez; S L Cartwright; R Castillo; M G Catanesi; A Cervera; D Cherdack; G Christodoulou; A Clifton; J Coleman; S J Coleman; G Collazuol; K Connolly; L Cremonesi; A Dabrowska; I Danko; R Das; S Davis; P de Perio; G De Rosa; T Dealtry; S R Dennis; C Densham; F Di Lodovico; S Di Luise; O Drapier; T Duboyski; K Duffy; F Dufour; J Dumarchez; S Dytman; M Dziewiecki; S Emery; A Ereditato; L Escudero; A J Finch; L Floetotto; M Friend; Y Fujii; Y Fukuda; A P Furmanski; V Galymov; S Giffin; C Giganti; K Gilje; D Goeldi; T Golan; M Gonin; N Grant; D Gudin; D R Hadley; A Haesler; M D Haigh; P Hamilton; D Hansen; T Hara; M Hartz; T Hasegawa; N C Hastings; Y Hayato; C Hearty; R L Helmer; M Hierholzer; J Hignight; A Hillairet; A Himmel; T Hiraki; S Hirota; J Holeczek; S Horikawa; K Huang; A K Ichikawa; K Ieki; M Ieva; M Ikeda; J Imber; J Insler; T J Irvine; T Ishida; T Ishii; S J Ives; E Iwai; K Iyogi; A Izmaylov; A Jacob; B Jamieson; R A Johnson; J H Jo; P Jonsson; C K Jung; M Kabirnezhad; A C Kaboth; T Kajita; H Kakuno; J Kameda; Y Kanazawa; D Karlen; I Karpikov; E Kearns; M Khabibullin; A Khotjantsev; D Kielczewska; T Kikawa; A Kilinski; J Kim; J Kisiel; P Kitching; T Kobayashi; L Koch; A Kolaceke; A Konaka; L L Kormos; A Korzenev; K Koseki; Y Koshio; I Kreslo; W Kropp; H Kubo; Y Kudenko; S Kumaratunga; R Kurjata; T Kutter; J Lagoda; K Laihem; I Lamont; M Laveder; M Lawe; M Lazos; K P Lee; T Lindner; C Lister; R P Litchfield; A Longhin; L Ludovici; M Macaire; L Magaletti; K Mahn; M Malek; S Manly; A D Marino; J Marteau; J F Martin; T Maruyama; J Marzec; E L Mathie; V Matveev; K Mavrokoridis; E Mazzucato; M McCarthy; N McCauley; K S McFarland; C McGrew; C Metelko; M Mezzetto; P Mijakowski; C A Miller; A Minamino; O Mineev; S Mine; A Missert; M Miura; L Monfregola; S Moriyama; Th A Mueller; A Murakami; M Murdoch; S Murphy; J Myslik; T Nagasaki; T Nakadaira; M Nakahata; T Nakai; K Nakamura; S Nakayama; T Nakaya; K Nakayoshi; D Naples; C Nielsen; M Nirkko; K Nishikawa; Y Nishimura; H M O'Keeffe; R Ohta; K Okumura; T Okusawa; W Oryszczak; S M Oser; R A Owen; Y Oyama; V Palladino; J Palomino; V Paolone; D Payne; O Perevozchikov; J D Perkin; Y Petrov; L Pickard; E S Pinzon Guerra; C Pistillo; P Plonski; E Poplawska; B Popov; M Posiadala; J-M Poutissou; R Poutissou; P Przewlocki; B Quilain; E Radicioni; P N Ratoff; M Ravonel; M A M Rayner; A Redij; M Reeves; E Reinherz-Aronis; F Retiere; A Robert; P A Rodrigues; P Rojas; E Rondio; S Roth; A Rubbia; D Ruterbories; R Sacco; K Sakashita; F Sánchez; F Sato; E Scantamburlo; K Scholberg; S Schoppmann; J Schwehr; M Scott; Y Seiya; T Sekiguchi; H Sekiya; D Sgalaberna; M Shiozawa; S Short; Y Shustrov; P Sinclair; B Smith; R J Smith; M Smy; J T Sobczyk; H Sobel; M Sorel; L Southwell; P Stamoulis; J Steinmann; B Still; Y Suda; A Suzuki; K Suzuki; S Y Suzuki; Y Suzuki; T Szeglowski; R Tacik; M Tada; S Takahashi; A Takeda; Y Takeuchi; H K Tanaka; H A Tanaka; M M Tanaka; D Terhorst; R Terri; L F Thompson; A Thorley; S Tobayama; W Toki; T Tomura; Y Totsuka; C Touramanis; T Tsukamoto; M Tzanov; Y Uchida; K Ueno; A Vacheret; M Vagins; G Vasseur; T Wachala; A V Waldron; C W Walter; D Wark; M O Wascko; A Weber; R Wendell; R J Wilkes; M J Wilking; C Wilkinson; Z Williamson; J R Wilson; R J Wilson; T Wongjirad; Y Yamada; K Yamamoto; C Yanagisawa; S Yen; N Yershov; M Yokoyama; T Yuan; M Yu; A Zalewska; J Zalipska; L Zambelli; K Zaremba; M Ziembicki; E D Zimmerman; M Zito; J Żmuda; T2K Collaboration

doi:10.1103/PhysRevLett.112.181801

Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam

Phys Rev Lett. 2014 May 9;112(18):181801. doi: 10.1103/PhysRevLett.112.181801. Epub 2014 May 8.

Authors

K Abe¹, J Adam², H Aihara³, T Akiri⁴, C Andreopoulos⁵, S Aoki⁶, A Ariga⁷, T Ariga⁷, S Assylbekov⁸, D Autiero⁹, M Barbi¹⁰, G J Barker¹¹, G Barr¹², M Bass⁸, M Batkiewicz¹³, F Bay¹⁴, S W Bentham¹⁵, V Berardi¹⁶, B E Berger⁸, S Berkman¹⁷, I Bertram¹⁵, S Bhadra¹⁸, F d M Blaszczyk¹⁹, A Blondel²⁰, C Bojechko²¹, S Bordoni²², S B Boyd¹¹, D Brailsford²³, A Bravar²⁰, C Bronner²⁴, N Buchanan⁸, R G Calland²⁵, J Caravaca Rodríguez²², S L Cartwright²⁶, R Castillo²², M G Catanesi¹⁶, A Cervera²⁷, D Cherdack⁸, G Christodoulou²⁵, A Clifton⁸, J Coleman²⁵, S J Coleman²⁸, G Collazuol²⁹, K Connolly³⁰, L Cremonesi³¹, A Dabrowska¹³, I Danko³², R Das⁸, S Davis³⁰, P de Perio³³, G De Rosa³⁴, T Dealtry³⁵, S R Dennis³⁶, C Densham⁵, F Di Lodovico³¹, S Di Luise¹⁴, O Drapier³⁷, T Duboyski³¹, K Duffy¹², F Dufour²⁰, J Dumarchez³⁸, S Dytman³², M Dziewiecki³⁹, S Emery⁴⁰, A Ereditato⁷, L Escudero²⁷, A J Finch¹⁵, L Floetotto⁴¹, M Friend⁴², Y Fujii⁴², Y Fukuda⁴³, A P Furmanski¹¹, V Galymov⁴⁰, S Giffin¹⁰, C Giganti³⁸, K Gilje², D Goeldi⁷, T Golan⁴⁴, M Gonin³⁷, N Grant¹⁵, D Gudin⁴⁵, D R Hadley¹¹, A Haesler²⁰, M D Haigh¹¹, P Hamilton²³, D Hansen³², T Hara⁶, M Hartz⁴⁶, T Hasegawa⁴², N C Hastings¹⁰, Y Hayato¹, C Hearty¹⁷, R L Helmer⁴⁷, M Hierholzer⁷, J Hignight², A Hillairet²¹, A Himmel⁴, T Hiraki²⁴, S Hirota²⁴, J Holeczek⁴⁸, S Horikawa¹⁴, K Huang²⁴, A K Ichikawa²⁴, K Ieki²⁴, M Ieva²², M Ikeda¹, J Imber², J Insler¹⁹, T J Irvine⁴⁹, T Ishida⁴², T Ishii⁴², S J Ives²³, E Iwai⁴², K Iyogi¹, A Izmaylov⁵⁰, A Jacob¹², B Jamieson⁵¹, R A Johnson²⁸, J H Jo², P Jonsson²³, C K Jung², M Kabirnezhad⁵², A C Kaboth²³, T Kajita⁴⁹, H Kakuno⁵³, J Kameda¹, Y Kanazawa⁵⁴, D Karlen⁵⁵, I Karpikov⁴⁵, E Kearns⁵⁶, M Khabibullin⁴⁵, A Khotjantsev⁴⁵, D Kielczewska⁵⁷, T Kikawa²⁴, A Kilinski⁵², J Kim¹⁷, J Kisiel⁴⁸, P Kitching⁵⁸, T Kobayashi⁴², L Koch⁴¹, A Kolaceke¹⁰, A Konaka⁴⁷, L L Kormos¹⁵, A Korzenev²⁰, K Koseki⁴², Y Koshio⁵⁹, I Kreslo⁷, W Kropp⁶⁰, H Kubo²⁴, Y Kudenko⁴⁵, S Kumaratunga⁴⁷, R Kurjata³⁹, T Kutter¹⁹, J Lagoda⁵², K Laihem⁴¹, I Lamont¹⁵, M Laveder²⁹, M Lawe²⁶, M Lazos²⁵, K P Lee⁴⁹, T Lindner⁴⁷, C Lister¹¹, R P Litchfield¹¹, A Longhin²⁹, L Ludovici⁶¹, M Macaire⁴⁰, L Magaletti¹⁶, K Mahn⁴⁷, M Malek²³, S Manly⁶², A D Marino²⁸, J Marteau⁹, J F Martin³³, T Maruyama⁴², J Marzec³⁹, E L Mathie¹⁰, V Matveev⁴⁵, K Mavrokoridis²⁵, E Mazzucato⁴⁰, M McCarthy¹⁷, N McCauley²⁵, K S McFarland⁶², C McGrew², C Metelko²⁵, M Mezzetto²⁹, P Mijakowski⁵², C A Miller⁴⁷, A Minamino²⁴, O Mineev⁴⁵, S Mine⁶⁰, A Missert²⁸, M Miura¹, L Monfregola²⁷, S Moriyama¹, Th A Mueller³⁷, A Murakami²⁴, M Murdoch²⁵, S Murphy¹⁴, J Myslik²¹, T Nagasaki²⁴, T Nakadaira⁴², M Nakahata⁶³, T Nakai⁶⁴, K Nakamura⁶⁵, S Nakayama¹, T Nakaya⁶⁶, K Nakayoshi⁴², D Naples³², C Nielsen¹⁷, M Nirkko⁷, K Nishikawa⁴², Y Nishimura⁴⁹, H M O'Keeffe¹⁵, R Ohta⁴², K Okumura⁶⁷, T Okusawa⁶⁴, W Oryszczak⁵⁷, S M Oser¹⁷, R A Owen³¹, Y Oyama⁴², V Palladino³⁴, J Palomino², V Paolone³², D Payne²⁵, O Perevozchikov¹⁹, J D Perkin²⁶, Y Petrov¹⁷, L Pickard²⁶, E S Pinzon Guerra¹⁸, C Pistillo⁷, P Plonski³⁹, E Poplawska³¹, B Popov³⁸, M Posiadala⁵⁷, J-M Poutissou⁴⁷, R Poutissou⁴⁷, P Przewlocki⁵², B Quilain³⁷, E Radicioni¹⁶, P N Ratoff¹⁵, M Ravonel²⁰, M A M Rayner²⁰, A Redij⁷, M Reeves¹⁵, E Reinherz-Aronis⁸, F Retiere⁴⁷, A Robert³⁸, P A Rodrigues⁶², P Rojas⁸, E Rondio⁵², S Roth⁴¹, A Rubbia¹⁴, D Ruterbories⁸, R Sacco³¹, K Sakashita⁴², F Sánchez²², F Sato⁴², E Scantamburlo²⁰, K Scholberg⁴, S Schoppmann⁴¹, J Schwehr⁸, M Scott⁴⁷, Y Seiya⁶⁴, T Sekiguchi⁴², H Sekiya¹, D Sgalaberna¹⁴, M Shiozawa⁶³, S Short²³, Y Shustrov⁴⁵, P Sinclair²³, B Smith²³, R J Smith¹², M Smy⁶⁰, J T Sobczyk⁴⁴, H Sobel⁶⁸, M Sorel²⁷, L Southwell¹⁵, P Stamoulis²⁷, J Steinmann⁴¹, B Still³¹, Y Suda⁵⁴, A Suzuki⁶, K Suzuki²⁴, S Y Suzuki⁴², Y Suzuki⁶³, T Szeglowski⁴⁸, R Tacik⁶⁹, M Tada⁴², S Takahashi²⁴, A Takeda¹, Y Takeuchi⁷⁰, H K Tanaka¹, H A Tanaka¹⁷, M M Tanaka⁴², D Terhorst⁴¹, R Terri³¹, L F Thompson²⁶, A Thorley²⁵, S Tobayama¹⁷, W Toki⁸, T Tomura¹, Y Totsuka⁷¹, C Touramanis²⁵, T Tsukamoto⁴², M Tzanov¹⁹, Y Uchida²³, K Ueno¹, A Vacheret¹², M Vagins⁶⁸, G Vasseur⁴⁰, T Wachala¹³, A V Waldron¹², C W Walter⁴, D Wark⁷², M O Wascko²³, A Weber³⁵, R Wendell¹, R J Wilkes³⁰, M J Wilking⁴⁷, C Wilkinson²⁶, Z Williamson¹², J R Wilson³¹, R J Wilson⁸, T Wongjirad⁴, Y Yamada⁴², K Yamamoto⁶⁴, C Yanagisawa², S Yen⁴⁷, N Yershov⁴⁵, M Yokoyama⁵⁴, T Yuan²⁸, M Yu¹⁸, A Zalewska¹³, J Zalipska⁵², L Zambelli³⁸, K Zaremba³⁹, M Ziembicki³⁹, E D Zimmerman²⁸, M Zito⁴⁰, J Żmuda⁴⁴; T2K Collaboration

Affiliations

¹ University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan.
² State University of New York at Stony Brook, Department of Physics and Astronomy, Stony Brook, New York, USA.
³ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and University of Tokyo, Department of Physics, Tokyo, Japan.
⁴ Duke University, Department of Physics, Durham, North Carolina, USA.
⁵ STFC, Rutherford Appleton Laboratory, Harwell Oxford, and Daresbury Laboratory, Warrington, United Kingdom.
⁶ Kobe University, Kobe, Japan.
⁷ University of Bern, Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), Bern, Switzerland.
⁸ Colorado State University, Department of Physics, Fort Collins, Colorado, USA.
⁹ Université de Lyon, Université Claude Bernard Lyon 1, IPN Lyon (IN2P3), Villeurbanne, France.
¹⁰ University of Regina, Department of Physics, Regina, Saskatchewan, Canada.
¹¹ University of Warwick, Department of Physics, Coventry, United Kingdom.
¹² Oxford University, Department of Physics, Oxford, United Kingdom.
¹³ H. Niewodniczanski Institute of Nuclear Physics PAN, Cracow, Poland.
¹⁴ ETH Zurich, Institute for Particle Physics, Zurich, Switzerland.
¹⁵ Lancaster University, Physics Department, Lancaster, United Kingdom.
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 York University, Department of Physics and Astronomy, Toronto, Ontario, Canada.
¹⁹ Louisiana State University, Department of Physics and Astronomy, Baton Rouge, Louisiana, USA.
²⁰ University of Geneva, Section de Physique, DPNC, Geneva, Switzerland.
²¹ University of Victoria, Department of Physics and Astronomy, Victoria, British Columbia, Canada.
²² Institut de Fisica d'Altes Energies (IFAE), Bellaterra (Barcelona), Spain.
²³ Imperial College London, Department of Physics, London, United Kingdom.
²⁴ Kyoto University, Department of Physics, Kyoto, Japan.
²⁵ University of Liverpool, Department of Physics, Liverpool, United Kingdom.
²⁶ University of Sheffield, Department of Physics and Astronomy, Sheffield, United Kingdom.
²⁷ IFIC (CSIC and University of Valencia), Valencia, Spain.
²⁸ University of Colorado at Boulder, Department of Physics, Boulder, Colorado, USA.
²⁹ INFN Sezione di Padova and Università di Padova, Dipartimento di Fisica, Padova, Italy.
³⁰ University of Washington, Department of Physics, Seattle, Washington, USA.
³¹ Queen Mary University of London, School of Physics and Astronomy, London, United Kingdom.
³² University of Pittsburgh, Department of Physics and Astronomy, Pittsburgh, Pennsylvania, USA.
³³ University of Toronto, Department of Physics, Toronto, Ontario, Canada.
³⁴ INFN Sezione di Napoli and Università di Napoli, Dipartimento di Fisica, Napoli, Italy.
³⁵ Oxford University, Department of Physics, Oxford, United Kingdom and STFC, Rutherford Appleton Laboratory, Harwell Oxford, and Daresbury Laboratory, Warrington, United Kingdom.
³⁶ STFC, Rutherford Appleton Laboratory, Harwell Oxford, and Daresbury Laboratory, Warrington, United Kingdom and University of Warwick, Department of Physics, Coventry, United Kingdom.
³⁷ Ecole Polytechnique, IN2P3-CNRS, Laboratoire Leprince-Ringuet, Palaiseau, France.
³⁸ UPMC, Université Paris Diderot, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Paris, France.
³⁹ Warsaw University of Technology, Institute of Radioelectronics, Warsaw, Poland.
⁴⁰ IRFU, CEA Saclay, Gif-sur-Yvette, France.
⁴¹ RWTH Aachen University, III. Physikalisches Institut, Aachen, Germany.
⁴² High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan.
⁴³ Miyagi University of Education, Department of Physics, Sendai, Japan.
⁴⁴ Wroclaw University, Faculty of Physics and Astronomy, Wroclaw, Poland.
⁴⁵ Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia.
⁴⁶ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and TRIUMF, Vancouver, British Columbia, Canada.
⁴⁷ TRIUMF, Vancouver, British Columbia, Canada.
⁴⁸ University of Silesia, Institute of Physics, Katowice, Poland.
⁴⁹ University of Tokyo, Institute for Cosmic Ray Research, Research Center for Cosmic Neutrinos, Kashiwa, Japan.
⁵⁰ IFIC (CSIC and University of Valencia), Valencia, Spain and Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia.
⁵¹ University of Winnipeg, Department of Physics, Winnipeg, Manitoba, Canada.
⁵² National Centre for Nuclear Research, Warsaw, Poland.
⁵³ Tokyo Metropolitan University, Department of Physics, Tokyo, Japan.
⁵⁴ University of Tokyo, Department of Physics, Tokyo, Japan.
⁵⁵ TRIUMF, Vancouver, British Columbia, Canada and University of Victoria, Department of Physics and Astronomy, Victoria, British Columbia, Canada.
⁵⁶ Boston University, Department of Physics, Boston, Massachusetts, USA and Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan.
⁵⁷ University of Warsaw, Faculty of Physics, Warsaw, Poland.
⁵⁸ University of Alberta, Centre for Particle Physics, Department of Physics, Edmonton, Alberta, Canada.
⁵⁹ Okayama University, Department of Physics, Okayama, Japan.
⁶⁰ University of California, Irvine, Department of Physics and Astronomy, Irvine, California, USA.
⁶¹ INFN Sezione di Roma and Università di Roma "La Sapienza," Roma, Italy.
⁶² University of Rochester, Department of Physics and Astronomy, Rochester, New York, USA.
⁶³ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan.
⁶⁴ Osaka City University, Department of Physics, Osaka, Japan.
⁶⁵ High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan and Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan.
⁶⁶ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and Kyoto University, Department of Physics, Kyoto, Japan.
⁶⁷ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and University of Tokyo, Institute for Cosmic Ray Research, Research Center for Cosmic Neutrinos, Kashiwa, Japan.
⁶⁸ University of California, Irvine, Department of Physics and Astronomy, Irvine, California, USA and Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan.
⁶⁹ University of Regina, Department of Physics, Regina, Saskatchewan, Canada and TRIUMF, Vancouver, British Columbia, Canada.
⁷⁰ Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Chiba, Japan and Kobe University, Kobe, Japan.
⁷¹ University of Alberta, Centre for Particle Physics, Department of Physics, Edmonton, Alberta, Canada and University of Bern, Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), Bern, Switzerland and Boston University, Department of Physics, Boston, Massachusetts, USA and University of British Columbia, Department of Physics and Astronomy, Vancouver, British Columbia, Canada and University of California, Irvine, Department of Physics and Astronomy, Irvine, California, USA and IRFU, CEA Saclay, Gif-sur-Yvette, France and University of Colorado at Boulder, Department of Physics, Boulder, Colorado, USA and Colorado State University, Department of Physics, Fort Collins, Colorado, USA and Duke University, Department of Physics, Durham, North Carolina, USA and Ecole Polytechnique, IN2P3-CNRS, Laboratoire Leprince-Ringuet, Palaiseau, France and ETH Zurich, Institute for Particle Physics, Zurich, Switzerland and University of Geneva, Section de Physique, DPNC, Geneva, Switzerland and H. Niewodniczanski Institute of Nuclear Physics PAN, Cracow, Poland and High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan and Institut de Fisica d'Altes Energies (IFAE), Bellaterra (Barcelona), Spain and IFIC (CSIC and University of Valencia), Valencia, Spain and Imperial College London, Department of Physics, London, United Kingdom and INFN Sezione di Bari and Università e Politecnico di Bari, Dipartimento Interuniversitario di Fisica, Bari, Italy and INFN Sezione di Napoli and Università di Napoli, Dipartimento di Fisica, Napoli, Italy and INFN Sezione di Padova and Università di Padova, Dipartimento di Fisica, Padova, Italy and INFN Sezione di Roma and Università di Roma "La Sapienza," Roma, Italy and Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia and Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa, Ch
⁷² Imperial College London, Department of Physics, London, United Kingdom and STFC, Rutherford Appleton Laboratory, Harwell Oxford, and Daresbury Laboratory, Warrington, United Kingdom.

PMID: 24856687
DOI: 10.1103/PhysRevLett.112.181801

Abstract

New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter θ23. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57×10(20) protons on target, T2K has fit the energy-dependent νμ oscillation probability to determine oscillation parameters. The 68% confidence limit on sin(2)(θ23) is 0.514(-0.056)(+0.055) (0.511±0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Δm32(2)=(2.51±0.10)×10(-3) eV(2)/c(4) (inverted hierarchy: Δm13(2)=(2.48±0.10)×10(-3) eV(2)/c(4)). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.