Time projection chambers for the T2K near detectors

The T2K experiment is designed to study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large Super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to better understand neutrino interactions at the energy scale below a few GeV. A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The data collected with the tracker is used to study charged current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. The tracker is surrounded by the former UA1/Nomad dipole magnet and the TPCs measure the charges, momenta, and particle types of charged particles passing through them. Novel features of the TPC design include its rectangular box layout constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and the calibration system

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

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

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)

Observation of Electron Neutrino Appearance in a Muon Neutrino Beam

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92 ± 0.55 expected background events. In the PMNS mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm232 and a CP violating phase δCP. In this neutrino oscillation scenario, assuming |Δm232|=2.4×10−3 eV2, sin2θ23=0.5, δCP=0, and Δm232>0 (Δm232<0), a best-fit value of sin22θ13 = 0.140+0.038−0.032 (0.170+0.045−0.037) is obtained

First muon-neutrino disappearance study with an off-axis beam

We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment

Identification of retinal vessels by color image analysis

International audienc

Composition of female pig fats : influence of the genetic type (LF, LB or PP) and changes during growth (between 40 and 100 kg)

International audienc

Constitutive and insect‐induced transcriptomes of weevil‐resistant and susceptible Sitka spruce

Abstract Spruce weevil (Pissodes strobi) is a significant pest of regenerating spruce (Picea) and pine (Pinus) forests in North America. Weevil larvae feed in the bark, phloem, cambium, and outer xylem of apical shoots, causing stunted growth or mortality of young trees. We identified and characterized constitutive and weevil‐induced patterns of Sitka spruce (Picea sitchensis) transcriptomes in weevil‐resistant (R) and susceptible (S) trees using RNA sequencing (RNA‐seq) and differential expression (DE) analyses. We developed a statistical model for the analysis of RNA‐seq data from treatment experiments with a 2 × 3 factorial design to differentiate insect‐induced responses from the effects of mechanical damage. Across the different comparisons, we identified two major transcriptome contrasts: A large set of genes that was constitutively DE between R and S trees, and another set of genes that was DE in weevil‐induced S‐trees. The constitutive transcriptome unique to R trees appeared to be attuned to defense, while the constitutive transcriptome unique to S trees was enriched for growth‐related transcripts. Notably, a set of transcripts annotated as “fungal” was detected consistently in the transcriptomes. Fungal transcripts were identified as DE in the comparison of R and S trees and in the weevil‐affected DE transcriptome of S trees, suggesting a potential microbiome role in this conifer‐insect interaction