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The first result of the MiniBooNE neutrino oscillation experiment

The first result of the MiniBooNE neutrino oscillation experiment. PRL98(2007)231801. Teppei Katori for the MiniBooNE collaboration Indiana University PMN07, Blaubeuren, July, 03, 07. The first result of the MiniBooNE neutrino oscillation experiment. PRL98(2007)231801.

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The first result of the MiniBooNE neutrino oscillation experiment

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  1. The first result of the MiniBooNE neutrino oscillation experiment PRL98(2007)231801 Teppei Katori for the MiniBooNE collaboration Indiana University PMN07, Blaubeuren, July, 03, 07 Teppei Katori, Indiana University, PMN07

  2. The first result of the MiniBooNE neutrino oscillation experiment PRL98(2007)231801 outline1. Conclusion2. LSND experiment3. Neutrino beam4. Events in the detector5. Cross section model6. Oscillation analysis7. Systematic error analysis8. The MiniBooNE initial results9. Low energy excess events10. Future plans Teppei Katori, Indiana University, PMN07

  3. 1. Conclusion Teppei Katori, Indiana University, PMN07

  4. 1. Conclusion Excluded region The observed reconstructed energy distribution is inconsistent with anmneappearance-only neutrino mass model MiniBooNE is incompatible withnmneappearance only interpretation of LSND at 98% CL Teppei Katori, Indiana University, PMN07

  5. 2. LSND experiment Teppei Katori, Indiana University, PMN07

  6. L/E~30m/30MeV~1 LSND signal 2. LSND experiment LSND experiment at Los Alamos observed excess of anti-electron neutrino events in the anti-muon neutrino beam. 87.9 ± 22.4 ± 6.0 (3.8s) LSND Collaboration, PRD 64, 112007 Teppei Katori, Indiana University, PMN07

  7. 2. LSND experiment Dm132 = Dm122 + Dm232 3 types of neutrino oscillations are found: LSND neutrino oscillation: Dm2~1eV2 Atmospheric neutrino oscillation: Dm2~10-3eV2 Solar neutrino oscillation : Dm2~10-5eV2 But we cannot have so many Dm2! New physics? - sterile neutrino - Lorentz violation - CPT violation - extra dimension - etc We need to test LSND signal! MiniBooNE experiment is designed to have same L/E~500m/500MeV~1 to test LSND Dm2~1eV2 Teppei Katori, Indiana University, PMN07

  8. 2. MiniBooNE experiment nm ne??? FNAL Booster target and horn decay region absorber detector K+ p+ Booster dirt primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) • Keep L/E same with LSND, while changing systematics, energy & event signature; • P(nm-ne) = sin22q sin2(1.27Dm2L/E) MiniBooNE has; - higher energy (~500 MeV) than LSND (~30 MeV) - longer baseline (~500 m) than LSND (~30 m) • MiniBooNE is looking for the single isolated electron like events, which is the signature of ne events Teppei Katori, Indiana University, PMN07

  9. 3. Neutrino beam Teppei Katori, Indiana University, PMN07

  10. 3. Neutrino beam Booster Target Hall FNAL Booster target and horn decay region absorber detector dirt nm ne??? K+ p+ Booster primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) MiniBooNE extracts beam from the 8 GeV Booster Teppei Katori, Indiana University, PMN07

  11. 3. Neutrino beam Magnetic focusing horn nm ne??? target and horn FNAL Booster decay region absorber detector K+ p+ Booster dirt primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) 8GeV protons are delivered to a 1.7 l Be target within a magnetic horn (2.5 kV, 174 kA) that increases the flux by  6 p- p+ p+ p- Teppei Katori, Indiana University, PMN07

  12. 3. Neutrino beam HARP experiment (CERN) Modeling Production of Secondary Pions - 5% l Beryllium target - 8.9 GeV proton beam momentum Data are fit to a Sanford-Wang parameterization. HARP collaboration, hep-ex/0702024 Teppei Katori, Indiana University, PMN07

  13. 3. Neutrino beam nm ne??? FNAL Booster target and horn decay region absorber detector K+ p+ Booster dirt primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) Decay pipe 50m decay pipe for pion decay in flight Teppei Katori, Indiana University, PMN07

  14. 3. Neutrino beam p m nm Km nm m e nm ne Kp e ne Neutrino Flux from GEANT4 Simulation MiniBooNE is the ne appearance oscillation experiment “Intrinsic”ne + nesources: • m+e+nm ne (52%) • K+ p0 e+ne (29%) • K0 p e ne (14%) • Other ( 5%) ne/nm = 0.5% Antineutrino content: 6% Teppei Katori, Indiana University, PMN07

  15. 4. Events in the Detector Teppei Katori, Indiana University, PMN07

  16. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo Teppei Katori, Indiana University, PMN07

  17. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo 541 meters Booster Teppei Katori, Indiana University, PMN07

  18. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo Teppei Katori, Indiana University, PMN07

  19. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo Teppei Katori, Indiana University, PMN07

  20. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo Extinction rate of MiniBooNE oil Teppei Katori, Indiana University, PMN07

  21. 4. Events in the Detector • The MiniBooNE Detector • - 541 meters downstream of target • - 3 meter overburden • - 12 meter diameter sphere • (10 meter “fiducial” volume) • - Filled with 800 t of pure mineral oil (CH2) • (Fiducial volume: 450 t) • - 1280 inner phototubes, • - 240 veto phototubes • Simulated with a GEANT3 Monte Carlo Teppei Katori, Indiana University, PMN07

  22. 4. Events in the Detector Times of hit-clusters (subevents) Beam spill (1.6ms) is clearly evident simple cuts eliminate cosmic backgrounds Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons >200 tank PMT hits Gets rid of Michels Only neutrinos are left! Beam and Cosmic BG Teppei Katori, Indiana University, PMN07

  23. 4. Events in the Detector Times of hit-clusters (subevents) Beam spill (1.6ms) is clearly evident simple cuts eliminate cosmic backgrounds Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons >200 tank PMT hits Gets rid of Michels Only neutrinos are left! Beam and Michels Teppei Katori, Indiana University, PMN07

  24. 4. Events in the Detector Times of hit-clusters (subevents) Beam spill (1.6ms) is clearly evident simple cuts eliminate cosmic backgrounds Neutrino Candidate Cuts <6 veto PMT hits Gets rid of muons >200 tank PMT hits Gets rid of Michels Only neutrinos are left! Beam Only Teppei Katori, Indiana University, PMN07

  25. 4. Events in the Detector • Muons • Sharp, clear rings • Long, straight tracks • Electrons • Scattered rings • Multiple scattering • Radiative processes • Neutral Pions • Double rings • Decays to two photons Teppei Katori, Indiana University, PMN07

  26. 4. Events in the Detector • Muons • Sharp, clear rings • Long, straight tracks • Electrons • Scattered rings • Multiple scattering • Radiative processes • Neutral Pions • Double rings • Decays to two photons Teppei Katori, Indiana University, PMN07

  27. 4. Events in the Detector • Muons • Sharp, clear rings • Long, straight tracks • Electrons • Scattered rings • Multiple scattering • Radiative processes • Neutral Pions • Double rings • Decays to two photons Teppei Katori, Indiana University, PMN07

  28. 4. Events in the Detector • Muons • Sharp, clear rings • Long, straight tracks • Electrons • Scattered rings • Multiple scattering • Radiative processes • Neutral Pions • Double rings??? • Decays to two photons??? • Looks like the electron (the biggest misID) Teppei Katori, Indiana University, PMN07

  29. 5. Cross section model Teppei Katori, Indiana University, PMN07

  30. 5. Cross section model Predicted event rates before cuts (NUANCE Monte Carlo) Casper, Nucl.Phys.Proc.Suppl. 112 (2002) 161 More detail at afternoon talk Teppei Katori, Indiana University, PMN07

  31. 6. Oscillation analysis Teppei Katori, Indiana University, PMN07

  32. 6. Blind analysis The MiniBooNE signal is small but relatively easy to isolate The data is described in n-dimensional space; hit time veto hits energy Teppei Katori, Indiana University, PMN07

  33. 6. Blind analysis CCQE ne candidate (closed box) The MiniBooNE signal is small but relatively easy to isolate The data is described in n-dimensional space; hit time NC veto hits high energy energy The data is classified into "box". For boxes to be "opened" to analysis they must be shown to have a signal < 1s. In the end, 99% of the data were available (boxes need not to be exclusive set) Teppei Katori, Indiana University, PMN07

  34. 6. Track-Based Likelihood (TBL) analysis log(Le/Lp) cut neCCQE neCCQE nm NCp0 Signal cut reconstructed pomass cut MC nm NCp0 MC nmCCQE ne CCQE This algorithm was found to have the better sensitivity tonmneappearance. Therefore, before unblinding, this was the algorithm chosen for the “primary result” Fit event with detailed, direct reconstruction of particle tracks, and ratio of fit likelihoods to identify particle Separating e from m Separating e from po Teppei Katori, Indiana University, PMN07

  35. 6. Track-Based Likelihood (TBL) analysis 475 MeV – 1250 MeV νeK94 νeμ132 π⁰ 62 dirt 17 Δ→Ng 20 other 33 total 358 LSND best-fit νμ→νe 126 TBL analysis summary - Oscillation analysis uses 475MeV<E<1250MeV Teppei Katori, Indiana University, PMN07

  36. 7. Systematic error analysis Teppei Katori, Indiana University, PMN07

  37. 7. Error analysis nmmis-id intrinsicne (TB analysis) We have two categories of backgrounds: many systematic errors are correlated (beam parameters, cross section model parameters, etc) MiniBooNE is very careful to propagate correlated systematic errors... Teppei Katori, Indiana University, PMN07

  38. 7. Multisim Output error matrix keep the correlation of EnQE bins Mtotal = M(p+ production) + M(p- production) + M(K+ production) + M(K0 production) + M(beam model) + M(cross section model) + M(p0 yield) + M(dirt model) + M(detector model) + M(data statistics) B.P.Roe, Nucl.,Instrum.,Meth,A570(2007)157 Oscillation c2 fit for EnQE distribution c2 = (data - MC)T (Mtotal)-1 (data - MC) Input error matrices keep the correlation of systematics dependent p+ production (8 parameters) p- production (8 parameters) K+ production (7 parameters) K0 production (9 parameters) beam model (8 parameters) cross section (27 parameters) p0 yield (9 parameters) dirt model (1 parameters) detector model (39 parameters) independent Multi-simulation method (Multisim) Teppei Katori, Indiana University, PMN07

  39. 8. The MiniBooNE initial results Teppei Katori, Indiana University, PMN07

  40. Open the box Teppei Katori, Indiana University, PMN07

  41. 8. The MiniBooNE initial results TBL analysis TBL show no sign of an excess in the analysis region Visible excess at low E BDT (Boosted Decision Tree) analysis BDT has a good fit and no sign of an excess Also sees an excess at low E, but larger normalization error covers it Teppei Katori, Indiana University, PMN07

  42. 8. The MiniBooNE initial results Conclusion: The observed reconstructed energy distribution is inconsistent with anmneappearance-only neutrino mass model Energy-fit analysis: solid: TB dashed: BDT Independent analyses are in good agreement. Excluded region Teppei Katori, Indiana University, PMN07

  43. 9. Low energy excess events Teppei Katori, Indiana University, PMN07

  44. 9. Excess at low energy region? Our goals for this first analysis were: (1) An analysis of the data within a nmne appearance-only context (2) A generic search for a ne excess in our nm beam (1) Within the energy range defined by this oscillation analysis, the event rate is consistent with background. (2) The observed low energy deviation is under investigation, including the possibility of more exotic model - Lorentz violation - 3+2 sterile neutrino - extra dimension etc... Teppei Katori, Indiana University, PMN07

  45. 9. Lorentz violation model Theoretical signals (no experimental smearing) It is possible to construct the global model for neutrino oscillation including Lorentz and CPT violation TK et al, PRD74(2006)105009 effective Hamiltonian This simple model is consistent with all existing neutrino oscillation data, including solar, atmospheric, reactor, and LSND. It predicts signal at low E region for MiniBooNE Fit with Lorentz violation model is under study. Teppei Katori, Indiana University, PMN07

  46. 10. Future plans A paper is accepted by PRL, PRL98(2007)231801 Many more papers supporting this analysis will follow, in the very near future: nm CCQE production, hep-ex/0706.0926, submitted to PRL p0 production MiniBooNE-LSND-Karmen joint analysis We are pursuing further analyses of the neutrino data, including... an analysis which combines TBL and BDT more exotic model for the LSND effect MiniBooNE is presently taking data in antineutrino mode. Teppei Katori, Indiana University, PMN07

  47. BooNE collaboration University of Alabama Los Alamos National Laboratory Bucknell University Louisiana State University University of Cincinnati University of Michigan University of Colorado Princeton University Columbia University Saint Mary’s University of Minnesota Embry Riddle University Virginia Polytechnic Institute Fermi National Accelerator Laboratory Western Illinois University Indiana University Yale University Thank you for your attention! Teppei Katori, Indiana University, PMN07

  48. 10. Back up Teppei Katori, Indiana University, PMN07

  49. 1. Neutrino oscillation Neutrino oscillation is a quantum interference experiment (cf. double slit experiment). n1 n2 If 2 Hamiltonian eigenstates, n1 and n2 have different phase rotation, they cause quantum interference. For double slit experiment, if path n1 and path n2 have different length, they have different phase rotations and it causes interference. Teppei Katori, Indiana University, PMN07

  50. 1. Neutrino oscillation Neutrino oscillation is a quantum interference experiment (cf. double slit experiment). Um1 n1 Ue1* nm ne n2 n1 n2 If 2 neutrino Hamiltonian eigenstates, n1and n2, have different phase rotation, they cause quantum interference. For massive neutrinos, if n1 is heavier than n2, they have different group velocities hence different phase rotation, thus the superposition of those 2 wave packet no longer makes same state as before Teppei Katori, Indiana University, PMN07

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