Measurements of neutrino oscillation in appearance and disappearance channels by the T2K experiment with 6.6 x 10(20) protons on target

111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee comments111 pages, 45 figures, submitted to Physical Review D. Minor revisions to text following referee commentsWe thank the J-PARC staff for superb accelerator performance and the CERN NA61/SHINE Collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC, and CFI, Canada; CEA and CNRS/IN2P3, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; RSF, RFBR and MES, Russia; MINECO and ERDF funds, Spain; SNSF and SER, Switzerland; STFC, UK; and the U. S. Deparment of Energy, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK, and the Emerald High Performance Computing facility in the Centre for Innovation, UK. In addition, participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; and DOE Early Career program, USA

Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 pi(0) detector

10 pages, 6 figures, Submitted to PRDhttp://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.112010© 2015 American Physical Society11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PRD11 pages, 6 figures, as accepted to PR

Measurement of proton, deuteron, triton, and alpha particle emission after nuclear muon capture on Al, Si, and Ti with the AlCap experiment

Background: Heavy charged particles after nuclear muon capture are an important nuclear physics background to the muon-to-electron conversion experiments Mu2e and COMET, which will search for charged lepton flavor violation at an unprecedented level of sensitivity. Purpose: The AlCap experiment aimed to measure the yield and energy spectra of protons, deuterons, tritons, and α particles emitted after the nuclear capture of muons stopped in Al, Si, and Ti in the low-energy range relevant for the muon-to-electron conversion experiments. Methods: Individual charged particle types were identified in layered silicon detector packages and their initial energy distributions were unfolded from the observed energy spectra. Results: The proton yields per muon capture were determined as Y p ( Al ) = 26.64 ( 28 stat. ) ( 77 syst. ) × 10 − 3 and Y p ( Ti ) = 26.48 ( 35 ) ( 80 ) × 10 − 3 in the energy range 3.5–20.0 MeV, and as Y p ( Si ) = 52.5 ( 6 ) ( 18 ) × 10 − 3 in the energy range 4.0–20.0 MeV. Detailed information on yields and energy spectra for all observed nuclei are presented in the paper. Conclusions: The yields in the candidate muon stopping targets, Al and Ti, are approximately half of that in Si, which was used in the past to estimate this background. The reduced background allows for less shielding and a better energy resolution in these experiments. It is anticipated that the comprehensive information presented in this paper will stimulate modern theoretical calculations of the rare process of muon capture with charged particle emission and inform the design of future muon-to-electron conversion experiments

Precise Measurement of the Neutrino Mixing Parameter theta(23) from Muon Neutrino Disappearance in an Off-Axis Beam

New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter theta_{23}. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57 x 10^{20} protons on target, T2K has fit the energy-dependent nu_mu oscillation probability to determine oscillation parameters. Marginalizing over the values of other oscillation parameters yields sin^2 (theta_{23}) = 0.514 +0.055/-0.056 (0.511 +- 0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Delta m^2_{32} = (2.51 +- 0.10) x 10^{-3} eV^2/c^4 (inverted hierarchy: Delta m^2_{13} = (2.48 +- 0.10) x 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

Measurement of the intrinsic electron neutrino component in the T2K neutrino beam with the ND280 detector

The T2K experiment has reported the first observation of the appearance of electron neutrinos in a muon neutrino beam. The main and irreducible background to the appearance signal comes from the presence in the neutrino beam of a small intrinsic component of electron neutrinos originating from muon and kaon decays. In T2K, this component is expected to represent 1.2% of the total neutrino flux. A measurement of this component using the near detector (ND280), located 280 m from the target, is presented. The charged current interactions of electron neutrinos are selected by combining the particle identification capabilities of both the time projection chambers and electromagnetic calorimeters of ND280. The measured ratio between the observed electron neutrino beam component and the prediction is 1.01 +/- 0.10 providing a direct confirmation of the neutrino fluxes and neutrino cross section modeling used for T2K neutrino oscillation analyses. Electron neutrinos coming from muons and kaons decay are also separately measured, resulting in a ratio with respect to the prediction of 0.68 +/- 0.30 and 1.10 +/- 0.14, respectively

T2K neutrino flux prediction

cited By 15 art_number: 012001 affiliation: Centre for Particle Physics, Department of Physics, University of Alberta, Edmonton, AB, Canada; Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics (LHEP), University of Bern, Bern, Switzerland; Department of Physics, Boston University, Boston, MA, United States; Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada; Department of Physics and Astronomy, University of California Irvine, Irvine, CA, United States; IRFU, CEA Saclay, Gif-sur-Yvette, France; Institute for Universe and Elementary Particles, Chonnam National University, Gwangju, South Korea; Department of Physics, University of Colorado at Boulder, Boulder, CO, United States; Department of Physics, Colorado State University, Fort Collins, CO, United States; Department of Physics, Dongshin University, Naju, South Korea; Department of Physics, Duke University, Durham, NC, United States; IN2P3-CNRS, Laboratoire Leprince-Ringuet, Ecole Polytechnique, Palaiseau, France; Institute for Particle Physics, ETH Zurich, Zurich, Switzerland; Section de Physique, DPNC, University of Geneva, Geneva, Switzerland; H. Niewodniczanski Institute of Nuclear Physics PAN, Cracow, Poland; High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan; Institut de Fisica d’Altes Energies (IFAE), Bellaterra (Barcelona), Spain; IFIC (CSIC and University of Valencia), Valencia, Spain; Department of Physics, Imperial College London, London, United Kingdom; INFN Sezione di Bari, Dipartimento Interuniversitario di Fisica, Università e Politecnico di Bari, Bari, Italy; INFN Sezione di Napoli and Dipartimento di Fisica, Università di Napoli, Napoli, Italy; INFN Sezione di Padova, Dipartimento di Fisica, Università di Padova, Padova, Italy; INFN Sezione di Roma, Università di Roma la Sapienza, Roma, Italy; Institute for Nuclear Research, Russian Academy of Sciences, Moscow, Russian Federation; Kobe University, Kobe, Japan; Department of Physics, Kyoto University, Kyoto, Japan; Physics Department, Lancaster University, Lancaster, United Kingdom; Department of Physics, University of Liverpool, Liverpool, United Kingdom; Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States; Université de Lyon, Université Claude Bernard Lyon 1, IPN Lyon (IN2P3), Villeurbanne, France; Department of Physics, Miyagi University of Education, Sendai, Japan; National Centre for Nuclear Research, Warsaw, Poland; State University of New York at Stony Brook, Stony Brook, NY, United States; Department of Physics and Astronomy, Osaka City University, Department of Physics, Osaka, Japan; Department of Physics, Oxford University, Oxford, United Kingdom; UPMC, Université Paris Diderot, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Paris, France; Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, United States; School of Physics, Queen Mary University of London, London, United Kingdom; Department of Physics, University of Regina, Regina, SK, Canada; Department of Physics and Astronomy, University of Rochester, Rochester, NY, United States; III. Physikalisches Institut, RWTH Aachen University, Aachen, Germany; Department of Physics and Astronomy, Seoul National University, Seoul, South Korea; Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom; University of Silesia, Institute of Physics, Katowice, Poland; STFC, Rutherford Appleton Laboratory, Harwell Oxford, Warrington, United Kingdom; Department of Physics, University of Tokyo, Tokyo, Japan; Institute for Cosmic Ray Research, Kamioka Observatory, University of Tokyo, Kamioka, Japan; Institute for Cosmic Ray Research, Research Center for Cosmic Neutrinos, University of Tokyo, Kashiwa, Japan; Department of Physics, University of Toronto, Toronto, ON, Canada; TRIUMF, Vancouver, BC, Canada; Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada; Faculty of Physics, University of Warsaw, Warsaw, Poland; Institute of Radioelectronics, Warsaw University of Technology, Warsaw, Poland; Department of Physics, University of Warwick, Coventry, United Kingdom; Department of Physics, University of Washington, Seattle, WA, United States; Department of Physics, University of Winnipeg, Winnipeg, MB, Canada; Faculty of Physics and Astronomy, Wroclaw University, Wroclaw, Poland; Department of Physics and Astronomy, York University, Toronto, ON, Canada references: Astier, P., (2003) Nucl. Instrum. Methods Phys. Res., Sect. A, 515, p. 800. , (NOMAD Collaboration), NIMAER 0168-9002 10.1016/j.nima.2003.07.054; Ahn, M., (2006) Phys. Rev. D, 74, p. 072003. , (K2K Collaboration), PRVDAQ 1550-7998 10.1103/PhysRevD.74.072003; Adamson, P., (2008) Phys. Rev. D, 77, p. 072002. , (MINOS Collaboration), PRVDAQ 1550-7998 10.1103/PhysRevD.77.072002; Aguilar-Arevalo, A., (2009) Phys. Rev. D, 79, p. 072002. , (MiniBooNE Collaboration), PRVDAQ 1550-7998 10.1103/PhysRevD.79.072002; (2003) Letter of Intent: Neutrino Oscillation Experiment at JHF, , http://neutrino.kek.jp/jhfnu/loi/loi_JHFcor.pdf, T2K Collaboration; Abe, K., (2011) Nucl. Instrum. Methods Phys. Res., Sect. A, 659, p. 106. , (T2K Collaboration), NIMAER 0168-9002 10.1016/j.nima.2011.06.067; Abe, K., (2011) Phys. Rev. Lett., 107, p. 041801. , (T2K Collaboration), PRLTAO 0031-9007 10.1103/PhysRevLett.107.041801; Abe, K., (2012) Phys. Rev. D, 85, p. 031103. , (T2K Collaboration), PRVDAQ 1550-7998 10.1103/PhysRevD.85.031103; Fukuda, Y., (2003) Nucl. Instrum. Methods Phys. Res., Sect. A, 501, p. 418. , NIMAER 0168-9002 10.1016/S0168-9002(03)00425-X; Beavis, D., Carroll, A., Chiang, I., (1995), Physics Design Report, BNL 52459Abgrall, N., (2011) Phys. Rev. C, 84, p. 034604. , (NA61/SHINE Collaboration), PRVCAN 0556-2813 10.1103/PhysRevC.84.034604; Abgrall, N., (2012) Phys. Rev. C, 85, p. 035210. , (NA61/SHINE Collaboration), PRVCAN 0556-2813 10.1103/PhysRevC.85.035210; Bhadra, S., (2013) Nucl. Instrum. Methods Phys. Res., Sect. A, 703, p. 45. , NIMAER 0168-9002 10.1016/j.nima.2012.11.044; Van Der Meer, S., Report No. CERN-61-07Palmer, R., Report No. CERN-65-32, 141Ichikawa, A., (2012) Nucl. Instrum. Methods Phys. Res., Sect. A, 690, p. 27. , NIMAER 0168-9002 10.1016/j.nima.2012.06.045; Matsuoka, K., (2010) Nucl. Instrum. Methods Phys. Res., Sect. A, 624, p. 591. , NIMAER 0168-9002 10.1016/j.nima.2010.09.074; Abe, K., (2012) Nucl. Instrum. Methods Phys. Res., Sect. A, 694, p. 211. , (T2K Collaboration), NIMAER 0168-9002 10.1016/j.nima.2012.03.023; Abgrall, N., (2011) Nucl. Instrum. Methods Phys. Res., Sect. A, 637, p. 25. , (T2K ND280 TPC Collaboration), NIMAER 0168-9002 10.1016/j.nima.2011.02. 036; Amaudruz, P.-A., (2012) Nucl. Instrum. Methods Phys. Res., Sect. A, 696, p. 1. , (T2K ND280 FGD Collaboration), NIMAER 0168-9002 10.1016/j.nima.2012.08. 020; Battistoni, G., Cerutti, F., Fasso, A., Ferrari, A., Muraro, S., Ranft, J., Roesler, S., Sala, P.R., (2007) AIP Conf. Proc., 896, p. 31. , APCPCS 0094-243X 10.1063/1.2720455; A. Ferrari, P. R. Sala, A. Fasso, and J. Ranft, Report No. CERN-2005-010A. Ferrari P. R. Sala A. Fasso J. Ranft Report No. SLAC-R-773A. Ferrari P. R. Sala A. Fasso J. Ranft Report No. INFN-TC-05-11R. Brun, F. Carminati, and S. Giani, Report No. CERN-W5013Zeitnitz, C., Gabriel, T.A., (1993) Proceedings of International Conference on Calorimetry in High Energy Physics, , in Elsevier Science B.V., Tallahassee, FL; Fasso, A., Ferrari, A., Ranft, J., Sala, P.R., Proceedings of the International Conference on Calorimetry in High Energy Physics, 1994, , in; Beringer, J., (2012) Phys. Rev. D, 86, p. 010001. , (Particle Data Group), PRVDAQ 1550-7998 10.1103/PhysRevD.86.010001; Eichten, T., (1972) Nucl. Phys. B, 44, p. 333. , NUPBBO 0550-3213 10.1016/0550-3213(72)90120-4; Allaby, J.V., Tech. Rep. 70-12 (CERN, 1970)Chemakin, I., (2008) Phys. Rev. C, 77, p. 015209. , PRVCAN 0556-2813 10.1103/PhysRevC.77.015209; Abrams, R.J., Cool, R., Giacomelli, G., Kycia, T., Leontic, B., Li, K., Michael, D., (1970) Phys. Rev. D, 1, p. 1917. , PRVDAQ 0556-2821 10.1103/PhysRevD.1.1917; Allaby, J.V., (1970) Yad. Fiz., 12, p. 538. , IDFZA7 0044-0027; Allaby, J.V., (1969) Phys. Lett. B, 30, p. 500. , PYLBAJ 0370-2693 10.1016/0370-2693(69)90184-1; Allardyce, B.W., (1973) Nucl. Phys. A, 209, p. 1. , NUPABL 0375-9474 10.1016/0375-9474(73)90049-3; Bellettini, G., Cocconi, G., Diddens, A.N., Lillethun, E., Matthiae, G., Scanlon, J.P., Wetherell, A.M., (1966) Nucl. Phys., 79, p. 609. , NUPHA7 0029-5582 10.1016/0029-5582(66)90267-7; Bobchenko, B.M., (1979) Sov. J. Nucl. Phys., 30, p. 805. , SJNCAS 0038-5506; Carroll, A.S., (1979) Phys. Lett. B, 80, p. 319. , PYLBAJ 0370-2693 10.1016/0370-2693(79)90226-0; Cronin, J.W., Cool, R., Abashian, A., (1957) Phys. Rev., 107, p. 1121. , PHRVAO 0031-899X 10.1103/PhysRev.107.1121; Chen, F.F., Leavitt, C., Shapiro, A., (1955) Phys. Rev., 99, p. 857. , PHRVAO 0031-899X 10.1103/PhysRev.99.857; Denisov, S.P., Donskov, S.V., Gorin, Yu.P., Krasnokutsky, R.N., Petrukhin, A.I., Prokoshkin, Yu.D., Stoyanova, D.A., (1973) Nucl. Phys. B, 61, p. 62. , NUPBBO 0550-3213 10.1016/0550-3213(73)90351-9; Longo, M.J., Moyer, B.J., (1962) Phys. Rev., 125, p. 701. , PHRVAO 0031-899X 10.1103/PhysRev.125.701; Vlasov, A.V., (1978) Sov. J. Nucl. Phys., 27, p. 222. , SJNCAS 0038-5506; Feynman, R., (1969) Phys. Rev. Lett., 23, p. 1415. , PRLTAO 0031-9007 10.1103/PhysRevLett.23.1415; Bonesini, M., Marchionni, A., Pietropaolo, F., Tabarelli De Fatis, T., (2001) Eur. Phys. J. C, 20, p. 13. , EPCFFB 1434-6044 10.1007/s100520100656; Barton, D.S., (1983) Phys. Rev. D, 27, p. 2580. , PRVDAQ 0556-2821 10.1103/PhysRevD.27.2580; Skubic, P., (1978) Phys. Rev. D, 18, p. 3115. , PRVDAQ 0556-2821 10.1103/PhysRevD.18.3115; Feynman, R.P., (1972) Photon-Hadron Interactions, , Benjamin, New York; Bjorken, J.D., Paschos, E.A., (1969) Phys. Rev., 185, p. 1975. , PHRVAO 0031-899X 10.1103/PhysRev.185.1975; Taylor, F.E., Carey, D., Johnson, J., Kammerud, R., Ritchie, D., Roberts, A., Sauer, J., Walker, J., (1976) Phys. Rev. D, 14, p. 1217. , PRVDAQ 0556-2821 10.1103/PhysRevD.14.1217; Abgrall, N., (2013) Nucl. Instrum. Methods Phys. Res., Sect. A, 701, p. 99. , NIMAER 0168-9002 10.1016/j.nima.2012.10.079; Hayato, Y., (2002) Nucl. Phys. B, Proc. Suppl., 112, p. 171. , NPBSE7 0920-5632 10.1016/S0920-5632(02)01759-0 correspondence_address1: Abe, K.; Institute for Cosmic Ray Research, Kamioka Observatory, University of Tokyo, Kamioka, Japan coden: PRVDA abbrev_source_title: Phys Rev D Part Fields Gravit Cosmol document_type: Article source: Scopu

Measurement of the nu(mu) charged-current quasielastic cross section on carbon with the ND280 detector at T2K

This paper reports a measurement by the T2K experiment of the νμ charged current quasielastic (CCQE) cross section on a carbon target with the off-axis detector based on the observed distribution of muon momentum (pμ) and angle with respect to the incident neutrino beam (θμ). The flux-integrated CCQE cross section was measured to be ⟨σ⟩=(0.83±0.12)×10−38  cm2. The energy dependence of the CCQE cross section is also reported. The axial mass, MQEA, of the dipole axial form factor was extracted assuming the Smith-Moniz CCQE model with a relativistic Fermi gas nuclear model. Using the absolute (shape-only) pμ−cosθμ distribution, the effective MQEA parameter was measured to be 1.26+0.21−0.18  GeV/c2 (1.43+0.28−0.22  GeV/c2)

Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation gamma rays

We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section gamma It is obtained by observing nuclear deexcitation. rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to 3.01 x 10(20) protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the 4-30 MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background is primarily nonquasielastic neutral-current interactions and has only 1.2 events from natural radioactivity. The flux-averaged NCQE cross section we measure is 1.55 x 10(-38) cm(2) with a 68% confidence interval of (1.22, 2.20) x 10(-38) cm(2) at a median neutrino energy of 630 MeV, compared with the theoretical prediction of 2.01 x 10(-38) cm(2)

Comparing early adolescents’ positive bystander responses to cyberbullying and traditional bullying: the impact of severity and gender

Young people are frequently exposed to bullying events in the offline and online domain. Witnesses to these incidents act as bystanders and play a pivotal role in reducing or encouraging bullying behaviour. The present study examined 868 (47.2% female) 11-13-year-old early adolescent pupils’ bystander responses across a series of hypothetical vignettes based on traditional and cyberbullying events. The vignettes experimentally controlled for severity across mild, moderate, and severe scenarios. The findings showed positive bystander responses (PBRs) were higher in cyberbullying than traditional bullying incidents. Bullying severity impacted on PBRs, in that PBRs increased across mild, moderate, and severe incidents, consistent across traditional and cyberbullying. Females exhibited more PBRs across both types of bullying. Findings are discussed in relation to practical applications within the school. Strategies to encourage PBRs to all forms of bullying should be at the forefront of bullying intervention methods

All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration < 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc^3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range 5 10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see also the public announcement at http://www.ligo.org/science/Publication-S6BurstAllSky