MiniBooNE Steve Brice Fermilab Overview MiniBooNE Beam MiniBooNE Detector Neutrino Analyses Summary Neutrino 2004 June 15 Steve Brice FNAL Page 1
� ✁ � ✁ ✁ Current Oscillation Signals Unconfirmed ∆ m 2 LSND ~ 0.1-10 eV 2 Well established measurements (Soudan, Kamiokande, MACRO, Super-K) ∆ m 2 atm ~ 2 - 3 x 10 -3 eV 2 (Homestake, SAGE, ∆ m 2 solar ~ 7 x 10 -5 eV 2 GALLEX, Super-K SNO, KamLAND) Neutrino 2004 June 15 Steve Brice FNAL Page 2
✂ ✂ ✂ ✄ ✂ ✂ Implications 3 active, light neutrinos (Z width from LEP) But ∆ m 2 solar + ∆ m 2 atm ≠ ∆ m 2 LSND If all 3 measurements are oscillations something fundamental has to give Sterile neutrino(s) are one possibility add extra neutrino flavours, but don't allow them to interact weakly Also affects offaxis sensitivity Sensitivity to exclude Null CP signal at 2 σ Black: No MiniBooNE Signal Red: if CPC MiniBooNE signal Blue: if CPV MiniBooNE signal Neutrino 2004 June 15 Steve Brice FNAL Page 3
✂ ☎ ✂ ✂ ✆ ☎ ✆ ☎ ✆ ☎ (hep-ex 0104049) The LSND Result LSND: Excess of ν e events in a ν µ beam 87.9 ± 22.4 ± 6.0 over background ~4 σ evidence for ν oscillation To Check LSND you want Experiment with different systematics higher statistics similar L/E MiniBooNE Neutrino 2004 June 15 Steve Brice FNAL Page 4
The Collaboration Y.Liu, I.Stancu University of Alabama S.Koutsoliotas Bucknell University E.Hawker, R.A.Johnson, J.L.Raaf University of Cincinnati T.Hart, R.H.Nelson, M.Wilking, E.D.Zimmerman University of Colorado A.A.Aguilar-Arevalo, L.Bugel, Fermilab J. M. Conrad, J. Link, J. Monroe, D.Schmitz, M. H. Shaevitz, IL, USA M. Sorel, G. P. Zeller Columbia University D.Smith Embry Riddle Aeronautical University L.Bartoszek, C.Bhat, S.J.Brice, B.C.Brown, D.A.Finley, B.T.Fleming, R.Ford, F.G.Garcia, P.Kasper, T.Kobilarcik, I.Kourbanis, A.Malensek, W.Marsh, P.Martin, F.Mills, C.Moore, P.Nienaber, E.Prebys, A.D.Russell, P.Spentzouris, R.Stefanski, T.Williams Fermi National Accelerator Laboratory D.C.Cox, A.Green, T.Katori, H. -O.Meyer, R.Tayloe Indiana University G.T.Garvey, C.Green, W.C.Louis, G.A.McGregor, S.McKenney, G.B.Mills, H.Ray, V.Sandberg, B.Sapp, R.Schirato, R.Van de Water, N.L.Walbridge, D. H. White Los Alamos National Laboratory R.Imlay, W.Metcalf, S.Ouedraogo, M.Sung, M.Wascko Louisiana State University J.Cao, Y.Liu, B.P.Roe, H.J.Yang University of Michigan A.O.Bazarko, P.D.Meyers, R.B.Patterson, F.C.Shoemaker, H.A.Tanaka Princeton University Neutrino 2004 June 15 Steve Brice FNAL Page 5
✞ ✝ ✞ ✞ ✝ ✞ MiniBooNE Goal Search for ν e appearance in a ν µ beam L=540 m ~10x LSND E~500 MeV ~10x LSND Aim to be definitive cover LSND 90% conf region at 4-5 σ this needs ~10 21 delivered protons Neutrino 2004 June 15 Steve Brice FNAL Page 6
✌ ✟ ✠ ✡ ☛ ☞ Beam Overview LMC Beamline Booster Decay Region 500m dirt Target and Horn Detector Primary Beam Secondary Beam Tertiary Beam (protons) (mesons) (neutrinos) Primary Beam 8 GeV protons from Booster Into MiniBooNE beamline Secondary Beam Mesons from protons striking Be target Focused by magnetic horn Tertiary Beam Neutrinos from meson decay in 50m pipe Pass through 500m dirt (and oscillate?) to reach detector Neutrino 2004 June 15 Steve Brice FNAL Page 7
✎ ✍ ✏ ✑ Booster Performance In its 30 years the Fermilab Booster has never worked this hard Currently average ... ~ 6x10 16 protons/hour Have reached 28% of total protons needed Neutrino 2004 June 15 Steve Brice FNAL Page 8
✣ ✚ ✛ ✘ ✤ ✗ ✜ ✖ ✕ ✙ ✔ ✓ ✒ ✢ Horn, Target Protons impinge on 71cm long, Be target & Fluxes Horn focusing of secondary beam increases ν flux by factor of ~5 170 kA pulses, 143 µ s long at ~5 Hz Has performed flawlessly with ~80 million pulses to date Main ν µ flux from π + µ + ν µ Intrinsic ν e flux from µ + ν µ e + ν e Κ + π 0 e + ν e π - e + ν e K 0 L Understand fluxes with multiple monitoring systems Neutrino 2004 June 15 Steve Brice FNAL Page 9
✦ ✥ ✧ ★ ✩ ✪ Understanding ν Fluxes (1) E910 @ BNL + previous world data fits Basis of current MB π production model HARP @ CERN Measure π & K production from 8 GeV p beam MB target slugs - thin and thick targets Analysis in progress Neutrino 2004 June 15 Steve Brice FNAL Page 10
✫ ✬ ✭ ✮ Understanding ν Fluxes (2) LMC muon spectrometer Κ decays produce wider angle muons than π decays LMC triggered from Scintillating fibre tracker 7 beam-on-target signal degrees off axis Neutrino 2004 June 15 Steve Brice FNAL Page 11
✱ ✲ ✵ ✯ ✰ ✴ ✳ Detector Overview 12m diameter sphere Filled with 950,000 litres of pure mineral oil Light tight inner region with 1280 8” PMTs (10% coverage) 240 PMTs in outer veto region Neutrino interactions in oil produce Prompt Č erenkov light Delayed scintillation light Neutrino 2004 June 15 Steve Brice FNAL Page 12
✶ Michel e Particle ID from µ decay candidate e − ν e W n p Beam µ candidate µ − ν µ W n p ν µ ν µ Z π 0 n ∆ 0 p Beam π 0 candidate Identify electrons (and thus candidate ν e events) from characteristic hit topology Neutrino 2004 June 15 Steve Brice FNAL Page 13
✸ ✷ ✹ ✺ ✻ Neutrino Candidates DAQ triggered on beam from Booster Detector read out for 19.2 µ s ν pulse through detector lasts 1.6 µ s With a few very simple cuts non- neutrino/neutrino rate is ~10 -3 Constant n rate per incident proton ν event every 1.5 minutes, ~300k to date Neutrino 2004 June 15 Steve Brice FNAL Page 14
✽ ✿ ❀ ✼ ✾ Laser Calibration System 4 Flasks distributed about the tank Measure tube charge response Measure tube timing response (needed for event reconstruction) (needed for energy measurement) Fully automated calibration system New calibration every 4 days Neutrino 2004 June 15 Steve Brice FNAL Page 15
● ❈ ◗ P ❖ ◆ ▼ ▲ ❑ ❏ ■ ❍ ❘ ❊ ❉ ❋ ❇ ❄ ❙ ❆ ❁ ❂ ❅ ❃ Optical Model Light Creation Cerenkov – well known Scintillation yield spectrum decay times In Situ Light Propagation Cosmics muons, Michel electrons, Laser Fluoresence Ex Situ rate Scintillation from p beam (IUCF) spectrum Scintillation from cosmic µ (Cincinnati) decay times Scattering Goniometry (Princeton) Rayleigh ( λ 4 , 1+COS 2 θ ) Fluorescence Spectroscopy (FNAL) Particulate (Mie) Time resolved spectroscopy (JHU) Absorption Attenuation (Cincinnati) Neutrino 2004 June 15 Steve Brice FNAL Page 16
❯ ❚ ❲ ❱ Muon Tracker and Cubes Muon tracker system provides muons of known direction in the tank Key to understanding energy and reconstruction 7 Scintillator cubes throughout the tank Provide muons & Michel electrons of known position Neutrino 2004 June 15 Steve Brice FNAL Page 17
❩ ❨ ❭ ❳ ❬ Electron Energy Response Cosmic Michel data Analytic fit Michel Electrons from Cosmic µ Decays Used to set energy scale 2 Events/0.005 GeV/c 700 MC signal + background 600 MC background Data 500 π 0 Mass Reconstruction PRELIMINARY 400 No. 0 ’s = 7208 144 π ± In Beam Time window 2 χ /NDF = 150.08/98 300 2 Mass = 0.1391 0.001 GeV/c ± Tank hits > 200, Veto hits < 6 200 In fiducial volume 100 Both rings > ~40MeV and well 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 separated 2 π 0 mass (GeV/c ) Neutrino 2004 June 15 Steve Brice FNAL Page 18
ν µ Analyses Use to understand CC quasi-elastic ν e CCQE cross-section resonant: background to ν e NC π 0 production appearance coherent: Z Use to understand Z NC elastic lower vertex p/n p/n Neutrino 2004 June 15 Steve Brice FNAL Page 19
❝ ❡ ❪ ❫ ❴ ❵ ❞ ❛ ❢ ❜ Charged 0.24 0.22 Data 0.2 MC: Φ , σ Shape Errors Current QE 0.18 MC: , Shape Errors + Φ σ 0.16 Optical Model Variations 0.14 0.12 Selection: 0.1 0.08 Cosmic ray cuts 0.06 0.04 Single µ -like ring 0.02 0 Topology 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 MC & Data relatively normalized. Visible Energy (GeV) Red Band: MC 1 σ uncertainty 0.2 Data 0.18 from... MC: , Shape Errors Φ σ 0.16 MC: Φ , σ Shape Errors + 0.14 flux shape Optical Model Variations 0.12 cross-section 0.1 0.08 Yellow Region: idea of variation 0.06 from... 0.04 0.02 optical properties (atten. length, 0 -1 -0.5 0 0.5 1 scintillation, scattering, ...) θ Cosine ( ) beam Neutrino 2004 June 15 Steve Brice FNAL Page 20
❤ ✐ ❣ 0.16 Data 0.14 MC: Φ , σ Shape Errors CCQE MC: Φ , σ Shape Errors + 0.12 Optical Model Variations 0.1 Reconstruction 0.08 0.06 0.04 0.02 Assume: (CCQE) 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 QE E (GeV) ν 0.3 CCQE and Q 2 from E µ , θ µ Get E ν Data 0.25 MC: Φ , σ Shape Errors MC: Φ , σ Shape Errors + 0.2 Optical Model Variations Sensitive to ν µ disappearance 0.15 0.1 0.05 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2 2 Q (GeV ) Neutrino 2004 June 15 Steve Brice FNAL Page 21
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