ICHEP 2004, Beijing H. Pessard/ OPERA - 1 The OPERA experiment CNGS long-baseline program in Europe  Search for  appearance in a  beam: prove    nature of atmospheric oscillation, measure  m 2  Search for   e oscillations (measure  13 ) OPERA Collaboration: Belgium, China, Croatia, France, Germany, Israel, Italy, Japan, Korea, Russia, Switzerland, Turkey H. Pessard (LAPP Annecy France), for the OPERA Collaboration Hall C Hall B ICARUS Gran Sasso underground lab OPERA CERN s Direct observation of  decay topology using nuclear photographic emulsions 35 groups, ~ 170 physicists (CNGS1)

ICHEP 2004, Beijing H. Pessard/ OPERA - 2 CERN Neutrinos to Gran Sasso 732 Km 11 Km CNGS beam optimized for  appearance:  E  = 17 GeV At 732 km in OPERA: 6200  CC+NC /year expected + 27   CC/year (  m 2 = eV 2 ) 400 GeV proton beam 4.5 x protons/year (7.6 x dedicated mode) 200 days/year,  = 55% ( e  e )   0.85 %    2.1 %  prompt negligible CNGS horns (Orsay)

ICHEP 2004, Beijing H. Pessard/ OPERA steel decay pipe installed 18 mm thick, 4.5 m Ø, + 50 cm of concrete Vacuum leak test on full 998 m tube OK CNGS beam construction at CERN on schedule First beam to Gran Sasso in May 2006 Intensity upgrade (x1.5) under study 3

ICHEP 2004, Beijing H. Pessard/ OPERA - 4 OPERA  appearance detection  CC events: detection of the  decay kink Pb Emulsion layers  1 mm e,      p,n, ,K... ,e,,e,          BR 17.4 % h     (n   )  49.5 % e     e 17.8 %          (n   )  15.0 % Based on the Emulsion Cloud Chamber (ECC) technique: emulsions for tracking, high Z plates as target ECC technique used in  discovery (DONUT-2000) Target mass ~1.8 Kton + film alignment  1  m  high modularity Basic unit: ECC “Brick” 56 lead plates 57 emulsion films 8.6kg 10 X x 12.7 x 7.5 cm Film base

ICHEP 2004, Beijing H. Pessard/ OPERA - 5 OPERA bricks and electronic detectors Trigger and localisation of interaction Spectrometer sections: 22 RPC planes in dipolar magnet 6 sections of Precision Trackers 1775 tons target: bricks ECC bricks alone can provide: - vertex and decay kink reconstruction - momentum measurement by MCS -  /  separation at low E by dE/dx - energy measurement of em showers,  identification of electrons 2 Super-Modules ~ 9m TEST experiment at CERN PS 1 mm 5 cm Target sections: 31 vertical “walls” of bricks 31 scintillation X-Y Target Tracker planes Muon ID, momentum, charge meas.

ICHEP 2004, Beijing H. Pessard/ OPERA - 6 OPERA hybrid detector operation Pb/Em. brick 8 cm - daily brick extraction (~30 bricks/day) by robot - cosmic ray exposure - film development 8 m Target Trackers Pb/Em. target Pb 1 mm Basic “cell” Emulsion Spectrometer trackers Electronic Data Acquisition in Gran Sasso - interaction tagging, brick selection - event  measurement Scanning stations in Japan and Europe - vertex location -  decay detection -  event full Data Acquisition: e/  ID, MCS,  /  separation, kinematics 3 2 1

ICHEP 2004, Beijing H. Pessard/ OPERA - 7 OPERA search for , topologies (1) Pick up all tracks from the interaction on the most downward film 5x5cm 2 for CC a film full surface for NC (2) Scan back picked up tracks (3) confirm interaction vertex; tracks stopped in 2 consecutive films (4) search for kink candidates (5) fully measure candidate events I.P. Short decays Pb Scanning power Pb Long decays Emulsion layers (not to scale ) Plastic base  kink  kink > 20 mrad  (  kink ) ~ 3 mrad Impact Parameter > 5 to 20  m (along Pb plate)  (I.P.) = 0.3 to 0.6  m

ICHEP 2004, Beijing H. Pessard/ OPERA - 8 Status of OPERA construction Brick Manipulator System Spectrometer sections: installation started May 2003 SM1 magnet complete June 2004 Target planes support SM2 magnet complete in April 2005 Target sections: installation starts September 2004

ICHEP 2004, Beijing H. Pessard/ OPERA - 9 OPERA magnets June 2004 Magnet 1: all 22 gaps filled with RPC slabs base B= 1.55 T coil 5 cm Fe slabs x 12 x 2 Total magnet weight 1000 tons  p  p  20-25%, charge mis-Id 0.3%  ID > 95% (Target Tracker + PT) May 2004 With Precision Tracker:

ICHEP 2004, Beijing H. Pessard/ OPERA - 10 OPERA in construction: summer 2004 July 2004

ICHEP 2004, Beijing H. Pessard/ OPERA - 11 Spectrometer RPC and Precision Tracker Nov 2003: 1 st plane of RPC installed May 2004: SM 1 fully equipped 462 RPC, 1540 m 2 (22 walls) 1160 RPC produced, Q-acceptance 70% Mechanical test, gas tightness HV, electrical tests in Ar Noise, Efficiency with cosmics Gas and HV tests repeated in Hall C prototype module Performance: efficiency: 99.1% resolution:  300 μm Installation: spring 2005 Drift tubes Tracker 4 layers, 8 m tubes 38 mm Ø, 50  m wire Simplified version of ATLAS drift tubes For 25%  P/P :  x ~ 0.5 mm, high  multi-hit 8 m

ICHEP 2004, Beijing H. Pessard/ OPERA - 12 Target Tracker and brick walls Construction of TT modules (64 strips) in progress: 8 modules/week X and Y planes, 6000m 2 in total - Scintillator strips (6.86m x 2.6cm x1cm): AMCRYS-H (Kharkov) above 5 p.e. specifs. - Kuraray WLS fibers 1000 MaPMT Hamamatsu 64-channels - Dedicated Front End electronics: gain correction auto-triggerable, 1/5 p.e. - Ethernet DAQ cards Brick wall full height prototype (6.7m) Well above 5 p.e. / readout end Target installation at LNGS: September December 2005

ICHEP 2004, Beijing H. Pessard/ OPERA - 13 ECC brick components: emulsion films, lead Film production started April 2003 (~ m 2 ) films made by Fuji Film Co. (joint R&D with Nagoya Univ.) 20% of 13 M films produced Film refreshing (erasure of CR tracks): facility in Tono Mine, Japan (700 bricks/day) being commissioned Film delivery at GS October 2004, CS May 2005 Refreshing parameters Humidity : > 95% Temperature : 30 ºC Time : ~ 3 days Pb plates 1mm thick  10  m - ready for prototype production at Goslar Co. - Pb/Ag/Al-Sn to replace Pb/Ca (compatibility with emulsions)

ICHEP 2004, Beijing H. Pessard/ OPERA - 14 Brick assembly BAM contracted Jan 2004 with Tecno-Cut (Swiss-Italian Co) Delivery at LNGS: April 2005 Brick assembly: Sep 2005, 1 year Filling SM1  March 2006 SM2  September 2006 Mechanical packaging adopted (long term tests):  less fragile than vacuum packaging  pressure produced by springs and fiberglass scotch tape  light tightness with Al adhesive tape Brick Assembly Machine (BAM) 2 bricks/min bricks Packaging Piling stations 40 m hall A/ hall B by-pass Lead handling

ICHEP 2004, Beijing H. Pessard/ OPERA - 15 Brick manipulator system Installation at LNGS: April 2005, Start detector brick filling: Sep Porticoes on each side of detector, to place platform in front of brick row Platforms  horizontal positioning  brick pushing in wall  brick retrieving vehicle Under construction and tests Storage carrousel

ICHEP 2004, Beijing H. Pessard/ OPERA - 16     Automatic scanning R&D in Nagoya and Europe S-UTS prototype at Nagoya Dedicated hardware Hard coded algorithms European station Commercial hardware Software algorithms   ~ 2mrad  x ~ 0.3  m 500 fps CMOS camera Bari, Bern, Bologna, Lyon, Napoli, Neuchâtel, Roma, Salerno Scanning lab to be European system: recent version working at 20 cm 2 /hr/side (15 to install) S-UTS system expected to reach similar performances (under completion)  Fast CCD camera (3 k frames/sec)  Continuous movement of the X-Y stage

ICHEP 2004, Beijing H. Pessard/ OPERA - 17 Channels considered at CNGS approval time (1999)   e (DIS+QE, long)     (DIS+QE, long)  Overall efficiency  DIS longQE longDIS shortOverall (weighted sum)   e      h Total % Efficiency increases under study: Brick finding efficiency improved analysis and strategy (+10%) BFE increase (?) with changeable sheet on the back side of the brick channel   3 prongs (1.0% additional efficiency, including BR 15%)  * BR OPERA  detection efficiencies Efficiencies include: BR, long/short, BFE, kink + kinematics cut,  Id and connection

ICHEP 2004, Beijing H. Pessard/ OPERA Total per channel Hadronic background Large angle μ scattering Charm background Total  h  h       e 5 years, nominal beam in red: possible BKGD reduction Charm background : Being re-evaluated using new CHORUS data: charm production increase by 40% (larger  c production), charm semileptonic BR down by 20%. In addition π/μ Id by dE/dx would reduce the charm background by 40%  being tested at KEK and this autumn at PSI (pure beam of π or μ stop) Large angle μ scattering : Upper limit from past measurements used so far Calculations including nuclear form factors give a factor 5 less  BKGD reduction will be checked in 2004 in X5 beam with Si detectors Hadronic background : Estimates based on Fluka standalone : 50% uncertainty. Error down to ~15%, improved sensitivity with extensive comparison of FLUKA with CHORUS data Expected number of background events

ICHEP 2004, Beijing H. Pessard/ OPERA - 19 Number of events in x10 19 pot / year 1.0 (1.5)19.9 (29.9)12.8 (19.2)8.0 (12.1) BFE improved by 10% + 3 prong decay 0.7 (1.1)16.4 (24.6)10.5 (15.8)6.6 (10.0)OPERA tons 0.8 (1.2) With possible BKGD 30% reduction BKGDsignal 3.0x eV 2 signal 2.4 x eV 2 signal 1.9 x eV 2 (...): with CNGS beam upgrade (x1.5)    sensitivity

ICHEP 2004, Beijing H. Pessard/ OPERA - 20 SK 90% CL (L/E analysis) Opera with beam x2 Opera with beam x3 Opera nominal Opera with beam x1.5, no BKGD reduction Opera nominal beam and half background Opera with beam x1.5, possible  improvements and BKGD reduction Sensitivity versus Beam Intensity (~equivalent)

ICHEP 2004, Beijing H. Pessard/ OPERA º5º x x Efficiency e CC beam  NC  CC eesignal  º7º º8º º9º Expected signal and backgrounds assuming 5 years data taking, nominal CNGS beam and  m 2 23 =2.5x10 -3 eV 2, sin 2 2  23 =1 simultaneous use of E visible, E electron and missing P t  7.1º  6.4º  0.06  0.05 (beam x1.5)  13 limit 90% CL sin 2 2  13 limit Sensitivity to  13 has a dependence on  CP complementary to T2K   e  sensitivity

ICHEP 2004, Beijing H. Pessard/ OPERA OPERA is looking for    oscillations (  appearance) and   e oscillations (measurement of   ) as part of the European long baseline Neutrino program - The OPERA collaboration since the approval in 2000 accomplished great progress towards the realisation of this large and delicate detector - Work is going on to improve the sensitivity by reducing the background and increasing the efficiency. The expected increase of the beam intensity will have a similar effect to secure the  appearance observation. - The CNGS beam and the OPERA experiment will start in 2006 Conclusions