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OPERA status

OPERA status. Outline:. OPERA experiment: from detector construction to a working apparatus Practical running update Past neutrino runs Detector target filling 2006-2007-2008 Data collection and analysis Statistics Prospects After April 6 L’Aquila seism. OPERA French groups

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OPERA status

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  1. OPERA status GDR Neutrino

  2. Outline: • OPERA experiment: from detector construction to a working apparatus • Practical running update • Past neutrino runs • Detector target filling • 2006-2007-2008 • Data collection and analysis • Statistics • Prospects • After April 6 L’Aquila seism OPERA French groups Annecy LAPP:D. Duchesneau, J. Favier, H. Pessard, A. Zghiche Lyon IPNL:D. Autiero, T. Brugière, A. Cazes, L. Chaussard, Y. Déclais, J. Marteau, E. Pennacchio, T. Tran Strasbourg IPHC:M. Dracos, C. Jollet, A. Meregaglia GDR Neutrino

  3. CERN OPERA 730 km LNGS OPERA • Long baseline experiment in Europe • Nuclear emulsion techniques • SK (1998): atmospheric neutrino anomaly interpretable as nmnt oscillation • CHOOZ: no nm→ne oscillation • SK nmdisappearanceoscillation signal confirmed by K2K and MINOS CNGS: 17 GeV nm beam from CERN to Gran Sasso OPERA: Direct observation of ντ appearance • From SPS: 400 GeV/c • Cycle length: 6 s • Extractions: • 2 separated by 50 ms • Pulse length: 10.5 ms • Beam intensity: • 2.4 1013 proton/extr. • Expected performance: • 4.5  1019 pot/year Gran Sasso underground laboratories: 1400 m rock overburden GDR Neutrino

  4. - nm m- nt nmB. R. ~ 17% h-ntn(po) B. R. ~ 50% e-nt neB. R. ~ 18% p+ p- p-ntn(po) B. R. ~ 14% n Experimental signature: tau neutrino CC detection CC interaction nm nt + N t-+ X oscillation t- n Decay “kink” nm oscillation t- - ct ~ 87 mm nt (≈ 600 mm of path) gct (with ≈ 35% of Non-Scaling QE and 65% DIS) no-oscillation (with ≈ 11% of Non-Scaling QE and 89% DIS) GDR Neutrino

  5. 1 mm   emulsion Pb 10.2cm Emulsion layers emulsion support 12.5cm The OPERA way to detect the tau kink ECC concept (Emulsion Cloud Chamber): 1 mm thick Pb layers interleaved with emulsions films (2 emulsion layers mthick poured on a 205m plastic base) Track reconstruction accuracy in emulsion: x 1 µm 1 mrad 10 X0 To reach O(Kton) mass, the OPERA lead–emulsion high granularity target is segmented into modular units called bricks One “BRICK” : - 57 emulsion films - 56 Pb plates - a box with a removable pair of films 150 000 bricks ~1.25 Ktons 8,6 Kg CS Changeable Sheet Doublet (CSd) GDR Neutrino

  6. RPC + drift tubes in spectrometers: • muon ID, • momentum, • charge • Target Trackers • neutrino trigger • brick localization The detector electronics racks Super Module 1 Super Module 2 Detector construction: Sept. 2003 - spring 2007 RPC Target ECCs scint. strips Veto Drift tubes Muon Spectrometer 10 m 20 m • BRICK WALLS • 53 walls filled with bricks • 2850 bricks/wall BMS Brick Manipulator system HIGH PRECISION TRACKERS 6 drift-tube layers/spectrometer spatial resolution < 0.5 mm • TARGET TRACKERS • 2 x 31 scintillator strips walls • 256+256 X-Y strips/wall • WLS fiber readout • 64-channel H7546 PMT • 63488 channels • 0.8 cm resol. • ε ≅ 99% • rate ≅ 20 Hz/pixel @1 p.e. • INNER TRACKERS • 990-ton Fe dipole magnets • (B= 1.55 T) instrumented with • 22 RPC planes (streamer mode) • 3050 m2,~1.3 cm spatial resol. • ε ≅ 96% (geometrical) GDR Neutrino

  7. OPERA performance as on-line detector OK (Negligible cosmics bg.) • CNGS-LNGS synchronization based on GPS. Present precision 100 ns (could be improved up to 10 ns) • DAQ live-time >99%. Live-time during CNGS 98.9% • Direction and momentum reconstruction for CNGS event • Charge and momentum reconstruction for cosmics OK In progress GDR Neutrino

  8. 1998 2000 2008 2010 2002 2004 2006 CNGS Approval CNGS runs @ CERN End of construction End of civil engineering Commissioning CNGS runs OPERA Elect-det only @ Gran Sasso 60000 bricks 150000bricks • 2006: short pilot run • No bricks. Stop due to horn cooling. • 2007 (24th September – 20th October): • 0.082 x 1019 pot. Only ~3.6 nominal days: radiation shielding problems. • 38 interactions in the bricks (32±6 expected) • 2008 (June 18th-November 3rd): • 1.782 x 1019 pot • 10100 events on time • ~1700 interactions in bricks • 0.7 t events expected 2008 first time long physics run, poor CNGS performance at beginning, better at the end (more CNGS cycles) GDR Neutrino

  9. CNGS Run 2008: 18 June- 03 Nov 2008 CNGS maintenance Total: 1.78·1019 pot Nominal: 4.5 1019 pot/yr Beam to CNGS, MD SPS extraction line: Magnet ground fault MD CNGS maintenance Beam to CNGS, LHC, FT SPS timing fault: vacuum leak & magnet exchange 18kV cable repair Beam to CNGS, LHC, FT, MD PSmagnet exchange, septum bakeout MD MD GDR Neutrino

  10. SFTPRO 3xCNGS LHC MD After the LHC accident, further increase of the intensity for OPERA (duty cycle 37.5% 83%). LHC MTE/CNGS 2xCNGS 4 x CNGS GDR Neutrino

  11. OPERA data taking flow • Trigger + event selection “on time” with CNGS • Brick finding reconstruction algorithm applied to electronic data to select the best candidate brick to contain the neutrino interaction vertex • Brick removed by the Brick Manipulation System (BMS) and exposed to (frontal) X-rays to make an alignment reference between CSd and brick • CSd detached from brick, films developed and analysed in one of the CSScanning Stations, in Europe (LNGS) or in Japan (Nagoya) • If a TT-predicted track is found in the CSd, the brick is exposed to (lateral) X-rays beam and to cosmic rays for sheets alignment. Brick is disassembled and emulsion films developed and sent to one of the scanning labs • Tracks found in the CSd are searched for in the most downstream film of the brick and followed (scan-back procedure) • A volume scan around the neutrino interaction point is performed and the neutrino vertex is located Brick assembly, manipulation, DB tracing, emulsion development and assoc. logistics were big engineering enterprises… Several ancillary facilities have been validated at nominal speed only in 2008 GDR Neutrino

  12. OPERA performance as hybrid detector Part. validated (*) Fully validated • Prediction of the brick where interaction occurred • Extraction of Bricks at the rate of CNGS events • Alignment and development of Changeable Sheets • Scanning of the Changeable Sheets • Identification of the primary vertex • Kinematic reconstruction and decay search Fully validated Fully validated In progress (**) In progress (**) (*) Extr. of 1° brick nearly completed. 2° in progress. (**) First results on a subsample of ~200 events GDR Neutrino

  13. Brick finding Check sample of extracted 1° bricks with CS scanned: 700 events (full stat. results will follow) Tracks found in the CS: 60%1st Brick finding (correct for dead material and CS efficiency): 70% (OK!) Expectation after 2nd extraction: 80%(check with real data in progress) Preliminary Manca plot Brick extractions End of CNGS run GDR Neutrino Up to 25 bricks per shift

  14. Scanning of Changeable Sheets LNGS (Italy) NAGOYA (Japan) MC independent test of track finding efficiency in CS in a subsample of fully located event (esb~ 90%) OK! Brick CSd LNGS n GDR Neutrino

  15. CSd nm 2 1 1 … 53 57 2 48 49 50 51 52 54 55 56 Vertex finding and decay search ‘data collection’ from emulsions CSd general scan: • 50 cm2 around TT prediction • angular range ±400 mrad • alignment by Xray marks (10mm accuracy) Scan back: • alignment using cosmic ray tracks (2mm accuracy) • stopping point Volume Scan: • 1 cm2, 10 plates Multiplicity m track IP • In progress: • vertex efficiency with large statistics • Backscattering studies • charm topologies search Test sample ~200 fully rec. events seems OK, full results need some more months. GDR Neutrino

  16. Vertex location summary, 2008 run PRELIMINARY Analysis April 3rd 2009 At least 1 CS track connected in brick: 96% Located events: 77% Passing through (wall misidentification): 6% Interactions in dead material: ~ 2% GDR Neutrino

  17. A beautiful  CC ECC level pair opening angle 10 mrad E = 157 MeV low p track GDR Neutrino 17

  18. Charm search 8 candidates found for 10 expected in a sample of ~550  CC A charm candidate PRELIMINARY vertex signature already evident in the CS Kink e.m. showers The charmed hadron is “inside” the hadronic jet and back to back with the muon  GDR Neutrino

  19. The charm decay kink Secondary Vertex (1 prong decay)‏ kink angle = 0.204 rad Decay length = 3247 μm p(daughter) = 3.9+1.7 -0.9 GeV pt = 796 MeV ptMIN= 606 MeV (90% CL) GDR Neutrino

  20. Consequences of the April 2009 L’Aquila seism • A strong earthquake (MI=6.3) hit the L’Aquila area on April 6th at 03:32 am. • 295 died, 1170 were hurt at L’Aquila and surrounding villages • The quake epicenter was only at 8.8 km depth, causing strong damages in a limited area. Many houses collapsed, 10 to 15000 buildings were damaged. 50K people are homeless. • 38K people still lived in tents last week, either homeless of fearing aftershocks (that lasted more than 2 weeks). • LNGS laboratories, ~20 km away, have no apparent damages. OPERA seems intact, although geometric measurements should be done to check its structure and alignment. • The most important problem for the lab is the situation of the staff. LNGS will officially reopen on May 5th. • Those dramatic circumstances will translate into some delay, all activities being stopped for 1.5 months: brick extractions and (re)insertions, CS scanning -> 2008 brick analysis are affected. GDR Neutrino

  21. Detector target filling situation 146405 bricks were produced and installed in the detector until July 2008 July 08 Mar 07 -3200 new bricks, produced after the recovery of the lead production chain (damaged by an explosion in 2008) were loaded to complete the OPERA target. Remain to be inserted: 2500 bricks • In preparation of the 2009 run, from February to April, the OPERA target was under a reshuffling operation needed to replace CS films in about 15000 bricks (10% of the whole target). About 8200 remain to be re-inserted. • About 300 candidate bricks from 2008 run remain to be extracted (2nd brick extraction). GDR Neutrino Target preparations for 2009

  22. Conclusions • In 2008, after a difficult startup, OPERA got from CNGS a significant integrated intensity (~2. 1019 p.o.t.). 2008 was OPERA first real physics run. • The construction of OPERA is complete; all sub-detectors and ancillary facilities are fully operative. • 4 months after the end of the data taking, most of the analysis chain has been validated. • The last steps, vertex and kinematic analysis of the full sample, will be completed in a few months. • Following the L’Aquila earthquake in April, CERN is awaiting a green light of OPERA to start the 2009 CNGS operation, hopefully with very little delay. • OPERA needs as many pots as possible soon to succeed in its physics program. GDR Neutrino

  23. The End GDR Neutrino

  24. -decay channels Background: Signal m2 = 2.5 x 10-3 eV2 e(%) BR(%) - µ- 2.9 0.17 17.5 17.7 -e- 3.5 0.17 20.8 17.8 - h- 3.1 0.24 5.8 49.5 - 3h 0.9 0.17 6.3 15 ALL 10.4 0.75 e x BR =10.6% Physics potential Full mixing, 5 years run, 4.5x1019 pot / year and target mass = 1.3 kton Expected background: • Charmed particles produced in nmCC and NC interaction • Hadron re-interactions in lead • Large angle scattering of muons produced in nm CC events • p0 misidentification Occurs if primary muon is not detected and possible wrong charge measurement of secondary muon. Muon ID is a crucial issue. GDR Neutrino

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