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Status Report on OPERA Experiments

This report provides an overview of the OPERA experiments, including the status of the container structures, target filling, brick production, and data collection. It also highlights the importance of muon identification and discusses background sources and commissioning issues. The report concludes with statistics on collected data and neutrino interactions.

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Status Report on OPERA Experiments

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  1. 37th Meeting of the LNF Scientific CommitteeOPERA Status Report Lucia Votano On behalf of the OPERA Collaboration Lucia Votano

  2. Containers for the emulsion-lead bricks (« walls ») OPERA-LNF General support structure F. Bersani Greggio, A. Cazes, V. Chiarella, C. Di Troia, B. Dulach, G. Felici, A. Franceschi, F. Grianti, T. Napolitano, M. Paniccia, A. Paoloni, M. Spinetti, F. Terranova, L. Votano In collaboration with LNF-SEA, LNF-SPAS, LNF-SSCR, LNF-DA_ Scintillators Magnets Veto RPC Drift tubes Brick insertion machine Automatic scanning of nuclear emulsion LNF projects Projects with partecipation of LNF Brick production machine (“BAM”) Lucia Votano Non-LNF projects

  3. t identification Neutrino Long event 40% Short event 60% Target is divided in about 151000 ECC’s 125mm 100mm 75.4mm II 10 X0 lead plate ECC （Emulsion Cloud Chamber） Piled up alternately Nuclear Emulsion (OPERA film) ～ 8.3 kg

  4. Sensitivity of tau neutrino detection Full mixing after 5 years run at 4.5x1019 pot / year Occur if primary muon is not detected and possible wrong charge measurement of secondary muon. Muon ID is very crucial issue for the experiment! Background sources: - Charm production and decays - Hadron re-interactions in lead - Large-angle muon scattering in lead

  5. 2003 : start building detector • January 2007: start filling target Brick Target Target mass 1.35 kt ~151000 Bricks ~8 millions of nuclear Emulsion Brick filling (146621 bricks)completed in July 2008: 4500 bricks will be produced at the end of 2008 once additional lead will be delivered after J.L. Goslar fire accident Lucia Votano

  6. 2008 CNGS neutrino run18 June -3 Nov 2008 1.78E19 pot 2007 CNGS neutrino run Sept-Oct 2007 8.24E17 pot • 2009 CNGS neutrino runrequested 4.5E19 pot ( nominal), scheduled 3.5E19 pot • (168 days 48s supercycle 80% efficiency 2.4E13 pot/extraction) Lucia Votano

  7. 2007 CNGS( OPERA 80% SM1 filled = 0.5 kton)  Sept-Oct 2007: 8.24x1017 integrated pot CNGS “Nominal”: 4.5 1019 pot /yr (1yr=200 days) 20/10/07 12/10/07 Comissioning Physics Problems in ventilation control units of the proton target 9/10/07 6.72 1017 pot 59 : CNGS very stable at 1.58 1017 pot/day 326expected events in bricks 38events registered: 29 CC 9 NC 5/10/07 3.91 1017 pot Time: in ns from 1/01/1970

  8. CNGS 2008 integrated intensity: 1.782E19 pot pot 3/11 8:00 1.782E19 pot CNGS “Nominal” : 4.5 1019 pot /yr (1yr=200 days) Horns filters 19-20/10 18KV cable accident 25/7 6-8/10 MD CNGS quadrupole 14-17/9 10/7-18/7 Earth fault on the PS magnet Beam loss, vacuum accident 27/6-2/7 Horn + PS vacuum Week 1/9 Wed 18/6 17:00 Start of commissioning at low intensity PS septum + Long MD 8-14/8 Long MD stop + MTE kicker problem 7/7 6:00 – 10/7 12:00 June 26th- November 3rd Unix Time

  9. 2008 Statistics • Duty cycle increased since September 24th (suppression of LHC pilot cycle) • Further increase after October 6th (stop of north area) • This allowed to partially recover the initial bad performance: Final statistics delivered by CNGS: 1.782E19 pot collected, (80% of the 2008 expectations) about 10100 on time events 1700 neutrino interactions in the bricks Important note: This year we had two different running conditions From June 26th June to September 24th : ~0.75x1019pot in 8 Unix Time Units From September 25th to November 3rd : ~1.03x1019pot in 3.5 Unix Time Units The event rate/day during the second period was ~25 (~170 events/week) Lucia Votano

  10. OPERA 2008 run (Electronic Detectors) Average rate Reference sample: long tracks (>5 TT planes) (x20) CNGS start: 18 june 2008 CNGS on-time events (x100) • 137 days of data taking • ~10.5 million events acquired • ~10100 events on time with CNGS • 1700 neutrino interactions in the bricks • The electronic detectors and the DAQ ran smoothly (99.96% efficiency for the target tracker during operation, loss of 2*1017 pot due to power cuts in LNGS) Lucia Votano

  11. OPERA working chain 1. Trigger on event “on time” with CNGS and selection of the brick using electronic detectors information (brick finding algorithm) 2. Brick removed by BMS (brick manipulating system) 3. The emulsion interfaces (CS) are separated from the brick, developed and a connection with respect to the electronic predictions is searched for in one of the two Scanning Stations, located in Europe (LNGS) and in Japan (Nagoya) 4. If any track is found in the CS, the brick is exposed to X-rays beam and to cosmic rays for sheets alignment 5. The brick is disassembled and the emulsion films are developed and sent to one of the scanning labs 6. The selected scanning lab acquire the brick, looking for the particles previously found in the CS and follow them until the neutrino interaction is found 7. A volume scan around the neutrino interaction is performed and the neutrino vertex is confirmed 8. The scanning lab stores the information about the brick in a local database. Information are then copied in one of the two synchronized central databases 9. The events are reconstructed and analyzed off-line by accessing to the database Lucia Votano

  12. Computing and DB • Electronic detector data • Online analysis performed in HallB; • Data are extracted twice a day: input for the brick finding; • Once a week data are copied into the central DB • Emulsion data • Each scanning lab has its own local database; • If a vertex is confirmed: data transferred into the the central DBs • Central DBs • We have two central DB: OPITA (located at the LNGS) and OPFRA (located at the CCIN2P3 in Lyon). • The central DBs contain: • electronic detectors data (including slow control data); • brick production & handling (BAM, BMS, film development…); • scanning data; • event reconstruction • Hardware and software: data storage and batch systems setup at the CCIN2P3 of Lyon Lucia Votano

  13. OPERA DB Oracle-based OPERA DB system Web service providing quick data access to summaries and reports AnalysisFollower Two Central DB servers (OPITA & OPFRA) collect data from specific DBs BMS Napoli Roma Frascati ElectronicDAQ OPFRA OPITA Emulsion Develop. Bern Bari Lyon Salerno Nagoya LNGS Bologna Padova Robust, redundant system Lucia Votano In case of hardware problems on either Central DB, the other can undertake the load of the failed machine

  14. The European Scanning System Z stage (Micos)0.05 μm nominalprecision Custom CMOS camera512×512 pixel3000 frames/sec CMOS camera1280×1024 pixel256 gray levels376 frames/sec(Mikrotron MC1310) Piezoelectric fine drivefor Z motion of lens Emulsion Plate X axis is drivenwith continuous motion XY stage (Micos)0.1 μm nominalprecision Oil objective 35× NA 0.85 Illumination system, objective (Oil 50× NA 0.85) and optical tube (Nikon) Mechanics based on Nikonmicroscope stages X/Y/Z nominal precision = 0.1mm The S-UTS (Japan) Emulsion scanning in OPERA State-of-art automated microscopes fast bi-dimensional image analysis real-time high precision 3D tracking • Scanning speed: 50 cm2/h/side average (72 cm²/h/side peak) custom parallel processing (FPGAs) • Purity: 10 fake tracks / cm2 (slope < 0.4) • Efficiency: 95% using tracks • Scanning speed: 20 cm2/h/side (40 GB/day/microscope of raw data) • Purity: 10 fake tracks / cm2 (slope < 0.5) • Efficiency: up to 95% using tracks, ~100% using microtracks • 0.3÷0.7 μm precision for recons. tracks

  15. Some numbers on brick handling and analysis flow as Nov. 16th CS delivered to the Scanning Stations CS scanned CS with a positive results Only Europe

  16. CSd measurement efficiency using muons 355 CSd analysed  352 events = 271 CC + 81 NC 213 developped bricks ~ 60% 167 CC 45 NC 124 with muon candidate 41 without muon candidate 74 ± 6% finding efficiency (80% expected) Independent estimate based on all tracks: e 74±4%  ebt86% to find a track in a single emulsion film Recently ¾ microtracks method implemented: ebt 89±3% (this option not yet applied to the analysis shown in the following)

  17. Estimate brick finding efficiency • Having measured the efficiency of the CSd in measuring a single track: 74% • Knowing that the #tracks/event is about 2 • 6.8% is the probability to miss the event in the CSd • Knowing that 3.8% interactions are in dead material • We can compute the brick finding efficiency: 67±5 (stat)% (MC predicts 72%) • Next steps: Removal of the 2nd most probable brick (MC exp. 80%)

  18. Vertex location breakdown by using a sub-sample of the measured events Vertex location efficiency: Charged-current: 90/(112-5-2) = 86±12% (108-5-2)/(112-5-2) = 96±13% In the proposal we quoted 93% Neutral-current: 20/(28-1) = 74±18% (25-1)/(28-1) = 89±22% In the proposal we quoted 81%

  19. Event gallery

  20. Found a 3 prong vertex in the bottom layer of the emulsion: 20

  21. ~20 GeV shower reconstructed

  22. Backward going particle 22

  23. Brick to brick connection Pasquale Migliozzi - XXX LNGS Committee - OPERA Status Report 23

  24. Topological and kinematical analysis - first charm-like event kink e.m.shower PRELIMINARY P=3.9+1.7-0.9 GeV kink=0.204 rad Daughter momentum = 3.9 +1.7-0.9 kink = 0.204 rad Flight length = 3247 µm PT = 796 MeV PTMIN = 606 MeV (90% C.L.) F.L.=3247.2m The main background source is the hadron reinteraction The probability that a hadron reinteraction has a Pt larger than 600 MeV is 4x10-4

  25. Topological and kinematical analysis - second charm-like event • From a topological point of view the main sources of background are: • Kaon decays: probability 10-4 • Hadron reinteractions: probability 1x10-5 • Further reduction from kinematical analysis. • A first result is shown here below Only 4-5 plates available for momentum measurement. Brick to brick is in progress 25

  26. First OPERA Brick measured @ LNF Emulsion Scanning lab Electronic-detectors muon track Vertex reconstruction in ECC µ µ

  27. Momentum distribution of reconstructed muon track Data = 4999 MC = 5123. • OpRec reconstructs the momentum of the track at the vertex, for internal events, or at the entrance of OPERA detector for external events. • The events are selected requiring: • on-time with CNGS • minimum activity in the detector • at least one OpRec track reconstructed • muID Fit: 3.4 ± 0.05 degree Pasquale Migliozzi - XXX LNGS Committee - OPERA Status Report 27

  28. OPERA EXECUTIVE SCHEME Spokesperson: A. Ereditato Deputy Spokesperson: K. Niwa Spokesperson Office: Composition: Two Vice-Spokespersons + 1 member (all appointed by the SP) Task: assist the SP in the executive management of the Collaboration. Members of the EB. Composition: P. Migliozzi (Vice-SP), F. Terranova (Vice-SP), M. Nakamura (NOTE: there is the proposal to appoint Deputy Spokespersons the two Vice-Spokesperson) Executive Committee: Technical Coordinator + Deputy: M. Spinetti + M. Nakamura Physics Coordinator +Deputy: D. Autiero + S. Dusini Scanning Coordinator + Deputy: G. De Lellis + O. Sato Resource Coordinator: L. Votano Detector Operation & Maintenance Coordinator: A. Paoloni Data Acquisition Coordinator: J. Marteau Brick Manipulation Coordinator: D. Duchesneau Emulsion Development Coordinator: C. Sirignano CNGS Neutrino Beam Coordinator: D. Autiero (pro tempore) Data Base Coordinator: C. Bozza Observer from the Collaboration Board: Y. Gornushkin 28

  29. Conclusions The OPERA detector and its infrastructures successfully operated during 2008 CNGS run Partial recovery of the beam after a rather problematic start: 1.782x1019 instead of 2.2x1019pot (80% of the expectations) About 1700 events in the bricks: < 1  but extremely valuable sample to fine tune OPERA analysis and to estimate efficiencies and background 2009 CNGS run aim is to at least double the integrated intensity and collect the first  candidate

  30. Brick handling chain 30

  31. OPERA DB DB-based Analysis Follower: Quasi on-line reporting on brick/event lifetime Brick/event history Event location feedback This WEB interface allows a direct and simple access to database contents to everybody Lucia Votano

  32. Emulsion development The development activity was able to follow the increase of the CSd scanning rate Still room for improvement Pasquale Migliozzi - XXX LNGS Committee - OPERA Status Report CS and brick development smoothly running since July Extended single shift mode: 11 h/d Mon-Frid. 8 people shift team (2 OPERA shifters, 6 operators). Average load: 30 CS doublets and 20 bricks per day 32

  33. Lucia Votano

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