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Long Baseline Neutrino Oscillation Experiments

Long Baseline Neutrino Oscillation Experiments. Alfons Weber RAL/University of Oxford RAL -Southampton Meeting RAL February 7, 2003. Contents . Introduction Long baseline experiments SNO KamLAND SuperKamiokande K2K MINOS OPERA ICARUS The Future Off-Axis Experiments

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Long Baseline Neutrino Oscillation Experiments

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  1. Long Baseline Neutrino Oscillation Experiments Alfons WeberRAL/University of OxfordRAL -Southampton Meeting RAL February 7, 2003

  2. Contents • Introduction • Long baseline experiments • SNO • KamLAND • SuperKamiokande • K2K • MINOS • OPERA • ICARUS • The Future • Off-Axis Experiments • Neutrino Factories LBL Experiments

  3. Introduction • Several indication for neutrino oscillations • Solar neutrino problem • Homestake, SAGE, GALLEX • Kamiokande, Super-Kamiokande, SNO • Atmospheric neutrino problem • Kamiokande, IMB, Frejus, NUSEX, Soudan 2, SuperK • LSND effect • LSND, KARMEN • New precision experiments are needed! • replace natural with man-made neutrino source • tune oscillation distance and energy to problem • Find out what the Neutrino oscillation matrix looks like! LBL Experiments

  4. Neutrino Mixing • Assume that neutrinos do have mass: • mass eigenstates  weak interaction eigenstates • Analogue to CKM-Matrix in quark sector! Mass eigenstates m1, m2, m3 weak“flavour eigenstates” Unitary mixing matrix: 3 mixing angles & 1 complex phase LBL Experiments

  5. Neutrino Oscillations • If mass and weak eigenstates are different: • Neutrino is produced in weak eigenstate • It travels a distance L as a mass eigenstate • It will be detected in a (possibly) different weak eigenstate • Simplified model with two neutrinos only: LBL Experiments

  6. Oscillation Signature measures m2 No effect! Smeared by resolutionP ~ 1/2 LBL Experiments

  7. The Solar Neutrino Problem • Different detectors (Super-K, Homestake, Gallex, Sage,…) • Different detection thresholds • All detectors observe neutrinoneutrino deficit • Reasons: • magnetic moment • neutrino oscillations Not enough electron neutrinos from the sun LBL Experiments

  8. The SNO Experiment LBL Experiments

  9. n +  + + - CC d p e e n +  + + n NC d p n x x ES - - +  + n e n e x x Neutrino Reactions in SNO p • well measured ne energy spectrum • weak angular dependence  1-1/3cos(q) • ne only • same cross section for all neutrinos • measures total 8B n-flux of the sun • few events • mainly sensitive to ne, (less to n and n ) • strong angular correlation LBL Experiments

  10. +1.01 Fssm = 5.05 -0.81 +0.44 +0.46 -0.43 -0.43 SNO Neutrino flux • Fsno = 5.09 LBL Experiments

  11. Interpretation combination of all experimental and solar model information LBL Experiments

  12. KamLAND • 1 kton LScint. detector in the Kamioka cavern • 1300 17” fast PMTs • 700 20” large area PMTs • 30% coverage • H2O veto counter • Multi-hit dead time-less electronics • Neutrinos from Japanese nuclear power plants (~160 km) • Δm2 sensitivity 710-6eV2 LBL Experiments

  13. KamLAND Collaboration S.Dazeley, K.Eguchi, S.Enomoto, K.Furuno, Y.Gando, J.Goldman, H.Hanada, H.Ikeda, K.Ikeda, K.Inoue, K.Ishihara, W.Ito, T.Iwamoto, H.Kinoshita, T.Kawashima, M.Koga, T.Maeda, T.Mitsui, M.Motoki, K.Nakajima, M.Nakajima, T.Nakajima, I.Nishiyama, H.Ogawa, K.Oki, T.Sakabe, I.Shimizu, J.Shirai, F.Suekane, A.Suzuki, O.Tajima, T.Takayama, K.Tamae, H.Watanabe Tohoku University T.Taniguchi KEK T.Chikamatsu Miyagi Gakuin Women's School H.Higuchi Tohoku-Gakuin University Y-F.Wang IHEP, Beijing J.Busenitz, Z.Djurcic, K.McKinny, D-M.Mei, A.Piepke University of Alabama B.Berger, R.N.Cahn, Y.D.Chan, X.Chen, S.J.Freedman, B.K.Fujikawa, K.T.Lesko, K.-B.Luk, H.Murayama, D.R.Nygren, C.E.Okada, A.W.Poon, H.M.Steiner LBNL/UC Berkeley L.Hannelius, G.A.Horton-Smith, R.D.McKeown, J.Ritter, B.Tipton, P.Vogel California Institute of Technology C.E.Lane Drexel University J.Learned, J.Maricic, S.Matsuno, S.Pakvasa University of Hawaii S.Hatakeyama, R.C.Svoboda Louisiana State University B.D.Dieterle, C.Gregory University of New Mexico J.Detwiler, G.Gratta, H-L.Liew, D.Murphree, N.Tolich, Y. Uchida Stanford University Y.Kamyshkov, W.Bugg, Y.Efremenko, H.Cohn, A.Weidemann, S.Berridge, M.Schram, M.Batygov, Y.Nakamura University of Tennessee L.Braeckeleer, C.Gould, C.L.HoeM.Hornish, H.Karwowski, D.Markoff, J.Messimore, K.Nakamura, R.Rohm, N.Simmons, W.Tornow TUNL LBL Experiments

  14. Detecting Neutrinos • Large(r) cross-section • Specific signature • e+ kinetic energy • (<8 MeV) • 2 annihilation γs • (0.5 MeV) • neutron capture • (2 to 8 MeV) ~2 events / day Neutrino energy measured from positron energy LBL Experiments

  15. KamLAND Event So… what does an event look like ? Charge: Red a lot, Bluelittle Time: Red soon, Blue late LBL Experiments

  16. Measure rate and energy spectrum of reactor neutrinos Clear confirmation of LMA KamLAND Results LBL Experiments

  17. Atmospheric Neutrinos • Atmosphere is bombarded by cosmic rays • Protons (H+) • nuclei (He, Li, …) • photons • … • some particles (1&2) produce hadronic shower • Neutrino ratio LBL Experiments

  18. The SuperKamiokande Experiment • H2O Cherenkov Detector • Proton decay • Neutrino interactions LBL Experiments

  19. SuperK Results • Atmospheric neutrinos • Muon neutrinos are missing! LBL Experiments

  20. Baseline: 250 km 1020 protons on target E = 12 GeV Neutrino energy: 1.4 GeV The K2K Experiment Prototype of a Long-Baseline-Experiments LBL Experiments

  21. K2K Results LBL Experiments

  22. The MINOS Experiment • NuMI beam to Soudan in MN (distance 735 km) • Sagitta:10 km • >1 km wide at destination LBL Experiments

  23. MINOS Detectors • There are 3 MINOS Detectors • Near detector @ FNAL (ND) • Far detector @ Soudan (FD) • Calibration detector @ CERN (CalDet) • Magn. steel-scintillator-tracking-calorimeter • alternating layers of steel and scintillator strips 12 ton 0.9 kton 5.4 kton LBL Experiments

  24. Photo by Jerry Meier MINOS Far Detector • Where? 27. Underground level of the Soudan Underground Mine State Park • Operated by theUniversity of MN for the DoE • ideal location • Tourist attraction: 40.000/year • well maintained • non operated mine MINOS cavern inblue LBL Experiments

  25. The MINOS Mural LBL Experiments

  26. MINOS planes 2-m wide, 0.5-inch thick steel plates Upper steel layer Scintillator planealternating orientations90o in successive planes Lower steel layer LBL Experiments

  27. Installation • Impressive progress • 80% personnel achieve 120% of the work • 400+ out of 484 planes are installed • normal data taking during installations LBL Experiments

  28. MINOS Oscillation Physics • Several channels to analyse neutrino oscillations • T-Test = #CC / #NC • ne appearance (q13) • Combination of all analysis will reveal mixing parameters • Dm2 • sin22q • flavour hadrons nμ μ nm disappearance 5 m nt appearance hadrons nμ nμ 1.5 m LBL Experiments

  29. Select nμ charge current events and reconstruct neutrino energy Energy resolution: Compare energy spectrum in near and far detector Measure m2 and sin22 nμ CC Energy Analysis range, B field calorimetric m2 sin22 LBL Experiments

  30. μDisappearance Results LBL Experiments

  31. First Neutrino Event Upward going Muon! Y t from below from above z LBL Experiments

  32. Atmospheric Neutrinos • Look for high energy muons (>1 GeV) • 4 years of data taking (18 kton years) • measure stopping and through-going muons • Energy measurement by magnetic field • Separation of neutrinos and anti-neutrinos! un-oscillated spectrum m2=10-3,sin2(2)=1.0 LBL Experiments

  33. CERN SPS Ep = 400 GeV 4.8*1013 ppp cycle 6 - 27.6 sec 7.6*1019 pot/year Baseline: 730km <E> = 17 GeV optimised for  neutrino appearance CNGS Beam CERN Neutrinos to Grand Sasso • Experiments • ICARUS • OPERA • try find  by searching for decay kink • nuclear emulsion LBL Experiments

  34. m spectrometer Magnetised Iron Dipoles Drift tubes and RPCs brick (56 Pb/Em. “cells”) n ~ 10 m 8 cm (10X0) module n target and t decay detector Each “super-module” is a sequence of 24 “modules” consisting of - a “wall” of Pb/emulsion “bricks” - planes of orthogonal scintillator strips brick wall scintillator strips The OPERA Experiment super module LBL Experiments

  35. Selected brick Sampling by Target Tracker planes ( X,Y ) Brick wall Event as seen by the target tracker 10 cm p.h. 0 max OPERA Target Section • Emulsion-Scintillator strip Hybrid Target • Tracker task • select bricks efficiently • High scanning power + low background allow coarse tracking Selected bricks extracted daily using dedicated robot LBL Experiments

  36. OPERA Emulsion Brick Origami packed ECC brick for OPERA • Vacuum packing • Protection against light and humidity variations. • Keep the positionbetweenfilms and lead plates. • Vacuum preserved over 10 years n 10X0 ( 56 emulsion films ) 12.5cm 235k bricks for 3 supermodules LBL Experiments

  37. OPERA  Candidates “ Long decays reconstruct kink topology “ Short decays  detect large impact parameter track Loose cut to reject low momentum tracks LBL Experiments

  38. 90 % CL limits * m2 ( 10-3 eV2 ) 1.5 3.2 5.0 Upper limit 2.1 3.8 5.6 Lower limit 0.8 2.6 4.3(U - L) / (2*True)41 % 19 % 12 % Nτ / year 0.822.82 3.66 OPERA 90 % CL in 5 years OPERA: m2 (mixing constrained by SuperK) * assuming the observation of a number of events corresponding to those expected for the given m2 Probability to observe SuperK signal LBL Experiments

  39. Physics • Nucleon Decay • Atmospheric Neutrinos • Solar Neutrinos • Beam Neutrinos (CNGS) • Technology • Liquid Argon TPC • 3D tracking • Scintillation light & PMTs trigger readout LBL Experiments

  40. Full 2D View from the Collection Wire Plane 2 Drift coord. (m) 2 1 3 2 Wire coord. (m) 2 4 6 12 18 1 El.m. shower 2 Zoom views m stop and decay in e Detail of a long (14 m) m track with d-ray spots 3 El.m. shower T600 test @ Pv: Run 201 - Evt 12 LBL Experiments

  41. ICARUS Sensitivity atmospheric beam Sensitivity similar to OPERA! LBL Experiments

  42. Sub-dominant Oscillation Modes • Main oscillation mode known • solar: • atmospheric: • Measure sub-dominant oscillation mode P (nm ne) = P1 + P2 + P3 + P4 LBL Experiments

  43. Measuring ne Oscillations • Needs • low ne beam contamination • narrow band beam (suppresses NC contamination) • NuMI Off-Axis • Beam already there ne background NC (visible energy), no rejection nm spectrum ne (|Ue32| = 0.01) LBL Experiments

  44. Detector Options • Detector on Surface • but 10-5 duty factor • Technologies (low Z) • MegaMINOS • Liquid Scintillator • Liquid Argon • RPCs • Requirements • good sampling • max: mass/radiation length • CHEAP!!!!!(20 kton, 400k ch) • Physics reach • oscillation probabilityaround 10-3 electron = fuzzy track LBL Experiments

  45. Phase II Increase beam power: 4 MW HyperKamiokande: 1 Mton Possibility of measuring CP-violation, if parameters are right! No need for -factory? New beam from JAERI 50 GeV, 0.77 MW 3.3*1014 ppp / 3.3 sec Phase I approved start operation 2007 Detector exists! J2K: JHF-SuperK LBL Experiments

  46. CP violation (phase II) Sensitivity (phase I) μ disappearance (1 year) SuperBeam Physics LBL Experiments

  47. Neutrino Factory • Muon storage ring: The Ultimate Neutrino Source LBL Experiments

  48. Neutrino Factory Physics LBL Experiments

  49. Summary • Present • K2K (re-starting now) • KamLAND (one year of data taking) • Future • MINOS (cosmics 2001, beam 2005) • OPERA (beam 2007) • ICARUS (2005, partially approved) • JHF-SuperK (2007, not yet approved) • NuMI off-axis (beam 2005, detector 2007+) • Science fantasy • Neutrino Factories (2010, at the earliest) LBL Experiments

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