1. The OPERA long baseline neutrino experiment: status and first results Luigi Salvatore Esposito Laboratori Nazionali del Gran Sasso on behalf of the OPERA collaboration

2. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito2 Summary Aim and strategy of the experiment OPERA detector CNGS 2007 run Neutrino interactions in a lead-emulsion target CNGS 2008 run Conclusions

3. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito3 The OPERA collaboration 36 INSTITUTIONS, ~200 PHYSICISTS Annecy, Lyon, Strasbourg Dubna, Moscow (INR,LPI,ITEP,SINP MSU) Obninsk Zagreb L’Aquila, Bari, Bologna, Frascati, LNGS, Napoli, Padova, Roma, Salerno Bern Neuchatel Zurich Brussels Hamburg, Münster, Rostock Sofia Aichi, Toho Kobe, Nagoya Utsunomiya Technion Haifa METU Ankara Gyeongsang

4. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito4 OPERA is designed for the direct observation of  appearance in a pure ν μ beam in order to provide a final confirmation of neutrino oscillations in the atmospheric sector Physics motivations best fit: M.C. Gonzalez-Garcia et M.Maltoni arXiv:0704.1800 [hep-ph]

5. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito5 The Cern Neutrino to Gran Sasso (CNGS) program CERN  beam optimized to study the  appearance by  detection Beam mean features: L=730 km ; =17 GeV  /  = 2.1% ( e + e )/  = 0.68%  prompt negligible 730 Km CERN LNGS

6. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito6 Detection of the  appearance signal The challenge is to identify  interactions from  interactions   -- Decay “kink”  -- ~1 mm  oscillation --      h -   n(    e -   e  +  -  -   n(    B. R. ~ 17% B. R. ~ 50% B. R. ~ 18% B. R. ~ 14%  decay modes OPERA solution is a hybrid technique: tracking apparatus with “many” Emulsion Cloud Chamber target units (lead/emulsion structure) Long-baseline, flavour oscillation: small fraction of  ν  : Far-away source, low flux, weak interaction: Long-baseline, flavour oscillation: small fraction of  ν  : Far-away source, low flux, weak interaction: →large targetmassrequired (as usual for ’s …) → large target mass required (as usual for ’s …) CC interactions of ν  tagged by the  decay (c  = 87 μm) : CC interactions of ν  tagged by the  decay (c  = 87 μm) : → need high spatial resolution & lepton Id → need high spatial resolution & lepton Id

7. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito7 Pb Emulsion layers  1 mm The brick is the target basic component: 57 nuclear emulsion films interleaved by 1 mm thick lead plates “Changeable Sheets doublet” made of two double refreshed emulsion films,vacuum packed and glued onto the bottom of each brick to connect TT- brick 2 emulsion layers (44  m thick) poured on a 205  m plastic base  130 000 m²  12.5cm 10.2cm 8.3 Kg 10 X 0 Electron track Emulsion: Measuring a vector in space (δx=1 μm δθ=1 mrad) The OPERA target is composed of 155000 bricks Emulsion analysis: Vertex, decay kink, e /  ID, multiple scattering, kinematics measurements on event-by-event basis! … limited by statistics The OPERA target

8. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito8 Target Tracker + Brick Walls Spectrometer  OPERA: a hybrid detector What the brick cannot do:  trigger for a neutrino interaction  muon identification and momentum/charge measurement  need a hybrid detector On-line analysis of electronic data Brick finding algorithm Selected brick is removed from the target and exposed to cosmic rays (alignment). Emulsions are developed and sent to scanning stations / labs

9. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito9 The OPERA detector SM1 SM2 Veto BMS Target tracker Spectrometer : XPC, HPT, RPC, magnet Modular, Hybrid Detector: Two supermodules, each containing a Target Section a Target Section - 31 Target Walls to host target units (ECC bricks) - 31 Target Walls to host target units (ECC bricks) - 31 Target Tracker modules (scintillator strips) - 31 Target Tracker modules (scintillator strips) a Magnetic Spectrometer (XPC, RPC, Drift tubes) a Magnetic Spectrometer (XPC, RPC, Drift tubes) Upstream: VETO (glass RPC) Upstream: VETO (glass RPC) Both sides: Brick Manipulation System (BMS) Both sides: Brick Manipulation System (BMS) Nearby: Brick Assembly Machine (BAM) - Hall B Nearby: Brick Assembly Machine (BAM) - Hall B Data Taking: (1) DAQ nodes + time stamp [Gran Sasso] Data Taking: (1) DAQ nodes + time stamp [Gran Sasso] (2) Emulsion scanning [Europe and Japan] (2) Emulsion scanning [Europe and Japan] … & several facilities for brick & emulsion film handling (X-ray systems, “Changeable sheets” refreshing and assembly, cosmic-ray exposure, film development) CNGS beam 19 m 10 m 8 m Hall C - Gran Sasso Underground Lab (Italy)

10. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito10 Status of brick production Brick Assembly Machine: piling/pressing section Brick Assembly Machine: wrapping section 9*10 6 emulsions & lead plates 155 000 bricks to be produced production rate ~ 700/day Filling under completion, ~ 88% now June 10 th July 28 th

11. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito11 High speed CCD Camera (3 kHz ) Piezo-controlled objective lens Constant speed stage Synchronization of objective lens and stage Off-line Data Taking ~ 30 bricks will be daily extracted from target and analyzed using high- speed automatic systems Several labs distributed in Europe and Japan S-UTS (Japan) Customized commercial optics and mechanics + asynchronous DAQ software Hard-coded algorithms scanning speed ~ 20 cm 2 / h European Scanning System Automated emulsion scanning

12. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito12 Automated emulsion analysis Predictions from electronic detectors are searched in the Changeable Sheet doublet. If an interaction is detected in the CS, the brick is exposed to cosmic rays (alignment) and the emulsions are developed and sent to scanning stations/labs The tracks measured in CSd are followed back inside the brick until tracks stop. A full scanning around neutrino interaction vertex is performed Finally the event topology and kinematics reconstructed is performed Emulsion scanning is performed in a fully automatic way. About 40 microscopes are operational in the various OPERA scanning laboratories (Europe and Japan).  CC interaction h muon 2 cm 2 mm ECC brick CS doublet

13. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito13 Track segments found in 8 consecutive plates Passing-through tracks rejection Vertex reconstruction Momentum measurement by Multiple Scattering dE/dx for  /µ separation at low energy Electron identification and energy measurement 3D reconstruction of particle tracks 16 tomographic images 2D Image processing 40  m emulsion sheet Emulsion scanning 200  m Field of view 0.2  m

14. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito14 Status of the experiment May 2003: start of detector construction May 2006: completion of electronic detectors commissioning Aug 2006: technical run, 0.76*10 18 pot collected 319 interactions in the rock, mechanical structure and iron of the spectrometer Oct 2006: start of brick production Oct 2007: short physics run (~40% target) 0.824*10 18 pot collected 38 events collected in the target May 2008: 135000 bricks inserted (~88% target) Jun 2008: OPERA target will be completed. Start of full data taking, expected about 2.1*10 19 pot in 130 days of SPS running.

15. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito15 2007 run: Interactions outside the Target 331 events passed the analysis cut 303 had been expected: ratio similar to the one observed in 2006 Muon vertical angleEnergy of the muon (RPC)

16. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito16 31.5 ± 6 expected events in bricks 38 events registered in the target (bricks + scintillators + walls  extra 10% contribution) during the 2007 CNGS run: 29 CC-like 9 NC-like Brick handling, Film Processing, Scanning : first test on real neutrino interactions 2007 run: Interactions inside the Target Event analysis is almost completed on this small sample Unfortunately statistics has been quite limited. Wall Finding: > 95% Brick Finding: 80%  7% Position accuracy: 2-3 cm

17. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito17  = 22 µ m  = 5 mrad CS to brick connection: design accuracy

18. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito18  = 54 µ m  = 9 mrad Systematical uncertainties (gap, marks, …) dominate CS to brick connection: neutrino interactions

19. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito19 Scan-back accuracy  = 4 µ m  = 2 mrad

20. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito20 Example of   CC interaction 5 prongs associated to the neutrino interaction = 9  m Electromagnetic shower pointing to the vertex (  conversion) 19 m 8 m 43 mm 17 mm

21. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito21 Charm candidate TrkTXTY IPMomentum(GeV) Comment 10.0050.0363.301.7 +0.5 -0.3 20.0050.1391.01-parent 30.0020.0646.64>20.0SB 4-0.0210.0647.152.1 +0.7 -0.4 SB 5-0.0290.0462.83>8.4SB 6-0.0310.0647.322.4 +0.8 -0.5 SB 7-0.0760.0684.191.8 +1.6 -0.6 SB 8-0.0890.1416.882.5 +1.4 -0.7 9-0.1830.1065.390.7 +0.2 -0.1 10-0.297-0.14319.170.7 +0.3 -0.1 11-0.0670.0087.263.5 +3.6 -1.2 e-pair 12-0.0690.00516.802.0 +3.1 -0.8 e-pair Secondary Vertex Daughter momentum = 3.9 +1.7 -0.9  kink = 0.204 rad Flight length = 3247 μm P t = 796 MeV P t MIN = 606 MeV (90% C.L.) Kink PRELIMINARY

22. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito22 OPERA τ search sensitivity  - decay channels Signal ÷  m 2 (Full mixing) Background 2.5 x 10 -3 (eV 2 )3.0 x 10 -3 (eV 2 ) -  µ--  µ- 2.94.20.17 -  e- -  e- 3.55.00.17 -  h- -  h- 3.14.40.24  -  3h 0.91.30.17 ALL10.415.00.76 5 years CNGS data taking ( 4.5 10 19 pot/year ) 1.35 ktons target mass

23. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito23 OPERA  observation probability SK 90% CL (L/E analysis) Discovery probability % Last MINOS measurement 3 σ sensitivity 4 σ sensitivity

24. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito24 The 2008 OPERA run 130 days for the CNGS (200) 2.1*10 19 p.o.t (4.5*10 19 ) Start: ~ June 20 th End: Nov 10 th Total number of interactions 2000  CC events 1500  NC events 450 e  e events 13 Charm decay85 Tau candidate (@2.5 10 -3 eV 2 ) ~ 1

25. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito25 The OPERA experiment is running - Electronic detectors fully commissioned - Target filling in progress (completed by June) Scanning labs are ready (~40 microscopes available) The OPERA 2007 run allowed to test the full operation chain: - Test electronic detectors and data acquisition - Test the brick finding algorithm - Test brick handling - Test CS doublet scanning - Test the target tracker to brick matching and scanning strategy The concept of the OPERA detector has been experimentally validated by measuring neutrino events in the detector. Conclusions In June the first high luminosity OPERA run will start. With some luck we will measure the first  candidate event by the end of this year!

26. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito26 BACKUP SLIDES

27. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito27 Time Selection of Beam Events GPS T CERN = Time Stamp SPS extraction T OPERA = Event TimeStamp T flight = 2.44 msec T OPERA - (T CERN + T flight ) < ∆T Gate GPS Time Stamp resolution ~ 100 ns

28. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito28 The 2006 commissioning run: CNGS and cosmics 50 ms 10.5  s August 2006 Integrated: 7.6x10 17 p.o.t. 319 “beam-related” events [New J. Phys. 8 (2006) 303]

29. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito29 τsearch: backgrounds  -- ,e ,e - +e+h++e+h+ D+D+ Same decay topology as  Charm production in CC, common to the 3 channels Good muon identification is fundamental Primary lepton not identified Coulombian large angle scattering of muons in Lead : Bck. to     Hadronic interactions in Pb: Bck. to  h or to    if hadron mis- identified as muon) Expected number of background events after 5 years running with nominal beam: h h τeτeτμτμτhτhτ  3h Total Charm background.173.008.134.181.496 Large angle μ scattering.096 Hadronic background.077.095..172 Total per channel.173.181.229.181.764

30. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito30   e oscillation search  13 SIGNAL e beam   e  NC  CC 9° 9.3 18 4.5 5.2 1.0 7° 5.8 18 4.5 5.2 1.0 5° 3.0 18 4.6 5.2 1.0  m 23 2  m 23 2 = 2.5 x 10 -3 eV 2  23 = 45° nominal CNGS beam Combined fit of E e, E vis, (pt) miss to improve S/B ratio 90% C.L. limits on sin 2 (2  13 ) and  13 : sin 2 (2  13 )<0.05  13 < 7.1º 5 years (pt) miss GeV 2.5x10 -3 eV 2 7.1 o 6.4 o

31. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito31 CNGS control electronics failure The failed ventilation electronics were installed along the TSG4 (service gallery), next to the ventilation ducts, and in the TCV4 (ventilation chamber). In both areas the radiation levels, as predicted by the FLUKA simulations and confirmed by the radiation protection measurements, are far too high for COTS components the electronics should have failed and they did!! Designated “radiation safe” areas for electronics electronic equipment

32. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito32 Actions for 2008 shutdown General guideline: Replace damaged electronics Replace damaged electronics Move the electronics out of the CNGS tunnels as possible Move the electronics out of the CNGS tunnels as possible For the equipment which must stay in the area: Create a “radiation-safe” area by adding adequate shielding and move all the electronics into this area Create a “radiation-safe” area by adding adequate shielding and move all the electronics into this area Address the sensitivity to radiation of the installed electronics and investigate upgrade possibilities Address the sensitivity to radiation of the installed electronics and investigate upgrade possibilities Install a radiation monitoring system for electronics as in LHC Install a radiation monitoring system for electronics as in LHC During the 2007/2008 shutdown, work is organized to remedy the problem and assure nominal running of the facility for 2008 and beyond. Radiation damages repair and protection: the work is fully funded electronics repair and reshuffling has started, shielding plugs defined, civil engineering starting completion of the work expected by the end of week 23 (June 6th) stable beam during week 25 (~June 20th)

33. 23-29 May, 2008 QUARKS-2008, Sergiev Posad L.S.Esposito33 Summary Event Location & Data analysis EuropeJapan All event 19 (15 CC, 4 NC)19 (14 CC, 5 NC) Events confirmed in the CSd18 Events located in the bricks1410 Interactions in dead material11 CS-Brick mismatch11 Analysis in progress26