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N eutrino oscillations in the CNGS n m beam

N eutrino oscillations in the CNGS n m beam. Shipping of an OPERA emulsion from Gran Sasso to Japan. The experimental challenge of direct detection of appearance through CC events The long-baseline era and the CNGS Nuclear emulsion-based techniques and the OPERA detector

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N eutrino oscillations in the CNGS n m beam

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  1. Neutrino oscillations in the CNGS nm beam Shipping of an OPERA emulsion from Gran Sasso to Japan The experimental challenge of direct detection of appearance through CC events The long-baseline era and the CNGS Nuclear emulsion-based techniques and the OPERA detector The 2008 run of the CNGS and OPERA First results from OPERA Conclusions and expectations for 2009: a special year at LNGS since also ICARUS T600 will enter the game! F. Terranova INFN-LNF

  2. Long-baselines at and after the 1998-2003 revolution 1998 2000 2008 2010 2002 2004 2006 CNGS Kamland Soudan-II SK-I Zenith NUMI Macro SNO-I SNO-II K2K-I K2K-II T2K Old Kamiokande analysis Ideal for a long baseline experiment with O(100 kW) beams At borderline for O (100 kW) technology: Nature has chosen for us a steep path! Out of reach for such technology

  3. A rewarding but troubled operation...(see e.g. E. Gschwendtner@Nufact08) NUMI target, horns and radiological issues K2K • Water leak soon after turn-on (March 2005)  ‘fixed’ with He backpressure holding back water from leak • September 2006: Target motion drive shaft locked due to corrosion  lead to target replacement • June 2008: Target longitudinal drive failure  In work cell repaired  reinstall K2K Horns in 2004: • No exchange due to high radiation • Nov 2004: Inner conductor of 1st horn broke • Radiation too high for replacement Horn problems: Ground fault, water line contamination by resin beads, water leaks at ceramic isolator… Tritium levels: major issue! Levels much greater than expected in water pumped from NuMI tunnel In general, startups are smooth: problems come ramping up to full power. CNGS was no exception.

  4. ...but appearance is an even steeper path... • Nature has been kind with us since it provided sources where oscillations are a leading effect • It has also been a bit malicious: • At solar scale, you cannot see explicitly a nenm transition through m CC production: no natural or man-made source are beyond the kinematical threshold for m production • At the atmospheric scale you have powerful nm source but... nmne transition are suppressed (“13 dilemma”). We must resort to looking for taus! • At long baseline (small Dm2) seeking for taus on an event-by-event basis is a major engeneering and experimental challenge: • It requires a beam O(10) more energetic than any other LBL • It requires a fine grained far detector O(100) more massive than its short-baseline ancestors (kton-size)

  5. 1998 2000 2008 2010 2002 2004 2006 Approval RUN End of construction End of civil engineering Commissioning [OPERA] Ele-det only 60000 bricks 150000 bricks CERN • 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 per extr • Expected performance: • 4.5  1019 pot/year Gran Sasso CNGS: a 17 GeV nm beam from CERN to Gran Sasso (732 km)

  6. The 2008 run can be considered the first physics run for the CNGS: • 2006 Pilot run: after commissioning in Aug, no follow-up in October due to a problem in the cooling of one horn. Moreover, no bricks in OPERA. • 2007: Major problems in the radiation shielding of the ventilation system. Only 8·1017 pot. Significant interventions during winter shutdown. • 2008 OPERA fully operational (see below). Performance of the CERN injection complex poor at beginning but steadily improving. • After the LHC accident, further increase of the integrated intensity for OPERA (duty cycle 37.5% 83%). SFTPRO 3xCNGS LHC MD LHC MTE/CNGS 2xCNGS 4x CNGS

  7. CNGS Run 2008: 18 June- 03 Nov 2008 CNGS maintenance Total: 1.78·1019 pot Beam to CNGS, MD Nominal: 4.5 1019 pot/yr for 5 years 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

  8. The completion of the OPERA construction(*) OPERA is based on the only proven technology (DONUT) to identify nt on an event-by-event basis (nucl.emuls.&lead driven by real time detectors). It will be firstly celebrated as a major engineering achievement since it brought such technology to an immense size (1.25 kton) (*) R.Acquafredda et al., “The Opera experiment in the CERN to GS n beam”; submitted to JINST

  9. 150036 brick have been produced and installed in the detector (1.25 kton mass) Jun 08 Mar 07 OPERA is an hybrid detector built running in parallel with several ancillary facilities that - before 2008 – hadn’t been validated at nominal speed, yet

  10. OPERA as a real-time detector OK [Negligible bkg from cosmics] • CNGS-LNGS syncronization: based on GPS. Present precision is 100 ns (can be improved up to 10 ns) • DAQ livetime >99%. Overall livetime during CNGS 98.9% • Collected events correlated with CNGS: 10122 on time (mainly in surrounding material) and 1663 in the target • Direction and momentum reconstruction for CNGS events • Charge and momentum reconstruction for off-time events (cosmic ray analysis) OK In progress

  11. OPERA as a hybrid detector Part. validated (*) Fully validated • Prediction of the brick where the interaction occurred • Alignment and development of the Changeable Sheets • Scanning of the Changable Sheets • Extraction of the Bricks at the rate of CNGS events • 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 below on a subsample of ~200 events

  12. Brick finding • Use data from the real-time detectors (scint hits, # p.e., identified tracks in the target and spectrometers) to build a probability map of the bricks where the interaction might have occurred • The most probable brick is extracted and the corresponding Changable Sheet is detatched and scanned • If tracks are found compatible with the expectations from the real time detectors  the brick is developed • Otherwise we try again with the second most probable brick Check sample of extracted 1° bricks with CS scanned: 700 events (full stat results will be released in a few weeks) 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

  13. Brick extraction from the detector Many operations in series: extraction, X-ray alignment, detachment of CS, development of CS, exposure of bricks to cosmic rays, development of bricks End of CNGS run Up to 25 bricks per shift (8h). OK! Also brick tracing in a DB, development and logistics have been a big engineering enterprise!

  14. Scanning of the 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

  15. Vertex finding and decay search The last link of the chain: It starts after CS confirmation, exposure of the brick to cosmics for alignment and development. In Japan, it is accomplished in the same site as for CS scanning, in Europe it is done in several laboratories. Testbed with about 200 fully reconstructed events seem OK; still a few months are needed to get full sample results. • In partucular: • Final numbers on vertex efficiency with large statistics • Backscattering studies • Search for charm topologies (2 found in the testbed sample: OK)

  16. Charm Three prongs

  17. Conclusions • After a troublesome startup, CNGS has delivered a significant integrated intensity in 2008 (~2 1019 p.o.t.). It represents the first real physics run for OPERA. • The construction of OPERA is over; the subdetectors and the ancillary facilities are fully operative. • Already after 4 months from the end of CNGS data taking, most of the analysis chain has been validated. A crucial milestone for this experiment. • We plan to complete the last steps (vertex and kinematic analysis of the full sample) in a few months - likely before the startup of 2009 run. A lot of physics can be drawn from this sample. Moreover, 0.7 taus are waiting for us  • What about 2009?...

  18. Perspectives for 2009 are good. Still only 3.5 of the nominal 4.51019 p.o.t. are expected this year. We’re a small fish in the storm of the LHC startup, but we appreciate the committment of CERN on the LBL programme; at the same time, we have the duty of keeping pressure on it for the success of the CNGS project. We’re here  The LHC startup

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