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Neutrino Oscillation Appearance with OPERA

Neutrino Oscillation Appearance with OPERA . Amina ZGHICHE . Oscillation Project with Emulsion tRacking Apparatus . Neutrino : a SM particle as any other. YES. It fits in the SM picture. N light_ n = 2.9840± 0.0082. arXiv:hep-ex /0509008 Phys.Rept .427:257-454,2006.

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Neutrino Oscillation Appearance with OPERA

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  1. Neutrino Oscillation Appearancewith OPERA Amina ZGHICHE Oscillation Project with Emulsion tRacking Apparatus

  2. Neutrino : a SM particle as any other YES • It fits in the SM picture Nlight_n= 2.9840± 0.0082 arXiv:hep-ex/0509008 Phys.Rept.427:257-454,2006

  3. Neutrino : a SM particle as any other? Not quite • Has a mass and Very low one (< 1 eV/c2) • Hint for physics beyond the SM • May be its own anti-particle • Only a weakly interacting particle • Produced as a coherent mix of three mass eigenstates in the weak interaction processes • Oscillates • Many parameters already precisely measured and some still not known

  4. Oscillation and mass: Uj : mixingmatrixelement • MNSPMaki-Nakagawa-Sakata-Pontecorvoneutrino mixing Matrix: 4 parameters to be determined +2 (∆m2) • Oscillation Probability:

  5. PANORAMA of the Oscillation measurements by DISAPPEARANCE (last 15 years) Minos Superkamiokande nmgnm nmgnm Neutrino beam (L ~730 km) 2005 atmosphericshowers(L ~20 et 12 000 km) 1998 SNO sun negne,m,t Reactor (L ~180 km) 2008 2000

  6. The appearance case with OPERA </15 ≈/6 ≈/4 Requirements: 1- High neutrino energy 2- High beam intensity 3- Long Baseline 4- Detection of short lived ‘s (10-12 s ) 5- Massive Underground detector

  7. CNGS Description Requirements1 and 2 SPS protons: 400 GeV/c • Every: 6 s, two pulses of 10.5 s separated by 50 ms • Proton pulses extracted by kicker magnet • Beam intensity: 2.0 x 1013 proton/extraction • ~ pure muon neutrino beam (<E> = 17 GeV)

  8. CNGS Experiments at LNGS Requirement 3 730

  9. Requirement 4 • Target basic unit: ECC brick = nuclear emulsion films interleaved by lead plates + 2 interface emulsion films (CS)  Massive target with micrometric space resolution • Electronic detectors to provide “time resolution” to the emulsion films and preselect the interaction region

  10. OPERA Detector +Requirement 5

  11. OPERA: POTs and Neutrino interactions Expected interactions for 22.5 1019 pot ~ 23600  CC+NC ~ 170 e + anti-e CC ~ 115  CC (∆m2 =2.5 x 10-3 eV2)

  12. Neutrinos seen by the OPERA Electronic detectorThe first data taking “EXTERNAL” CC-EVENTS (neutrino interactions in the rock) -like “INTERNAL or contained” EVENTS With µ • µCC • τCC,   (17.4%) Without µ or NC-like • NC • τCC,  e (17.8%) • τCC,  h, 3h (49.2%,15.2%) • eCC

  13. OPERA Sensitivity to Neutrino Oscillations

  14. The background Primary lepton not identified. Good (95%)  identification mandatory Coulomb large angle scattering of  in Pb () Charm production in CC (all channels) - -,e- ,e    D+ + e+ h + h h Hadron interactions in Pb(h) • 5 years of nominal beam (4.5 1019pot/year) • All channels: BR*global efficiency ~8% • Possible additional kinematical variable analysis ( h) • Need solid understanding of hadronic system by comparing to real data (CC)

  15. OPERA DETECTOR FEATURES

  16. The OPERA FIRST Data Taking with Electronic Detectors: ONLINE  beam veto RPC+HPT+Magnetmuon spectrometer muon Id, sign and momentum measurement Brick wall and Target Tracker 15K bricks=1.25Kton 31 walls per Super Module Each Brick wall is followed by a Target Tracker plane For the interaction preselect ion (trigger) and the event localization (brick finding)

  17. Brick finding  beam • BMS (LAPP-Annecy): • Twin Brick Manipulating System • one on each side of the detector. • They run over z,x axis , • 18mx10m with a precision of 1-2mm • And push 26 bricksx8Kg through ~3m • Filled the target and now used to extract • the candidate brick

  18. The OPERA SECOND Data Taking with SCANNING

  19. Event Location and vertex reconstruction Scan Back Low Energy tracks High Energy tracks Volume Scan

  20. Impact parameter separation power into a decay search process IP distribution for ντ events(MC)

  21. Momentum Measurement N Agafonovaet al 2012 New J. Phys.14 013026 Momentum measurement by Muliple Coulomb Scarering in the lead/emulsion film sandwich and comparison with electronic detector measurements

  22. Calibration with µCC charm eventsSimilar lifetime and decay topology 49 events detected, 51. 0± 7.5 expected

  23. OPERA → 

  24. First  candidate event2008-2009 decay search, released in 2010 (Phys. Lett. B (2010) 138) 2010

  25. Second  candidate event 2012

  26. Background expectation for the analyzed data (preliminary) Main background is charm events associated with muon Id failure 0.05 BG event expected for the second candidate Summary of the data processing

  27. PANORAMA of the Oscillation measurements by APPEARANCE (LAST 3 YEARS) (LBL) OPERA with CNGS beam nmgnt 2010 730 km A 2ndteventobserved in 2012 ntg t-+ hadrons et t-gpop- T2K with JPARC beam nmgne 10 candidates back exp. 2.37 295 km 250km 2011

  28. Lead to the major breakthrough: q13 measurement T2K : nmgne LBL appearance of ne T2K 10 candidates back exp. 2.37 Reactorswithdisappearance ofne negne • 3 experiments: • Double Chooz (France) • Daya Bay (China) • Reno (Korea) 2012 sin22q13 = 0.094 (±10%) q13large => good for mass hierarchy determination and CP violation searches

  29. OPERA → e 5.3x1019 pot - 2008-2009 data

  30. OPERA as an electromagnetic (em) calorimeter 56mm of Pb=10X0 Three steps with a NN algorithm: - Shower Reconstruction - Identification (separation from pions) - Energy estimation Preliminary MC Standard volume Energy Resolution ID efficiency/5films Preliminary MC em Shower energy(GeV) Shower extension(# films)

  31. Multi Variable analysis of the → e oscillation channel • (1-MC-preliminary) → e CNGS e → e NC → e CNGS e → e NC Preliminary MC → e CNGS e → e NC → e CNGS e → e NC

  32. Multi Variable analysis of the → e oscillation channel(2-MC-preliminary) Without MVA: Signal/BG =0.058 With MVA: Signal/BG=0.22 (~4 times improvement) BG suppression needs to be improved

  33. → e search through e.m. showers in the data Event sample: 505NC--‐like events in 2008 and 2009 For each located event (all tracks found) – Extrapolate each track up to the CS – Search the shower pattern (3 or more track element )on CS – scan back additional volume from the CS hint and perform the e.m. shower reconstruction if found. – 86 events with showers selected – 19 e events confirmed

  34. DATA – MC comparison (preliminary) Data - BG MC -SIGNAL MC Data - BG MC -SIGNAL MC Visible Energy Electron Energy  angle Data - BG MC -SIGNAL MC Data - BG MC -SIGNAL MC Missing PT Compatible , not significant for oscillation

  35. OPERA Oscillation Results at Neutrino2012: 2008-2009 data 5.3x1019 pot S and BG Compatible , not significant for oscillation After low energy event selection (Eν < 20GeV): Observed νe events: 4 Expected νe events: Oscillated νe events :1.1 Beam νe BG events : 3.7 Observed νe events : 19 Expected νe events: Oscillated νe events :1.5 Beam νe BG events :19.2

  36. Any other non standard oscillation ICARUS:arXiv:1209.0122v3 Standard three flavour mixing Window left by the full OPERA statistic for sterile?

  37. Neutrino velocity Synchroni -zation • 2 TWIN high accuracy timing system • Common View Mode CNGS • Proton pulses individually measured (1 ns sampling) • Time stamped and logged in the CERN DB OPERA • Time distributions of the ON TIME events

  38. 2012 measurement with CNGS bunched beam

  39. Results for neutrino velocityJHEP(2013)153 δtν = (0.7 ± 0.4(stat) ± 1.6(syst.-uncorr.) ± 2.5(syst.-corr)) ns

  40. Conclusion • OPERA experiment: aimed the direct detection of νμ→ντoscillations in APPEARANCE MODE, successfully taking data since 2008, • Total integrated luminosity: ~18.0x1019pot ~= 80% of the nominal value (22.5 x 1019) • 2 νμ→ντcandidate events: τ→1 prong: τ →ρ(π-π0)ντ τ→3 h ντ 1.9 signal and 0.18 background expected • Preliminary result on the νμ→νeoscillation analysis 19 events observed, 4 with energy < 20 GeV (expected osc. Signal 1.1, BG 3.9) constraints in the high Δm2region but no final answer foreseen New improved result under final discussion within the collaboration • About 56% of the data has still to go through the second data taking (scanning…) and analysis • Neutrino velocity measurement: 2012 bunched beam result: δtν = (0.7 ± 0.4(stat) ± 1.6(syst.-uncorr.) ± 2.5(syst.-corr)) ns

  41. THANK YOU FOR THE ATTENTION

  42. OPERA sensitivity Full mixing and Δm223~2.4x10‐3eV2 The green hashed band indicates the OPERA allowed region (90%CL) for the above parameter value and for 22.5x1019 pot

  43. 6 parameters Precision 2s m212 7.54 10-5 eV² 2.43 10-3 eV² 0.307 0.386 0.024 21% 5% 7% 11% 12% |m223 | sin² q12 sin² q23 sin² q13 d Valeur ? Where we stand in 2012 Signe ? Ref: G.L. Fogli et al. arXiv:1205.5254v3 Échelle de masse ?

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