Скачать презентацию The OPERA experiment H Pessard LAPP Annecy France Скачать презентацию The OPERA experiment H Pessard LAPP Annecy France

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

CERN Neutrinos to Gran Sasso 11 Km 732 Km 400 Ge. V proton beam CERN Neutrinos to Gran Sasso 11 Km 732 Km 400 Ge. V proton beam 4. 5 x 1019 protons/year (7. 6 x 1019 dedicated mode) 200 days/year, e = 55% ( e+ e) / 0. 85 % / 2. 1 % prompt negligible CNGS beam optimized for appearance: = 17 Ge. V At 732 km in OPERA: 6200 CC+NC /year expected + 27 CC/year (Dm 2= 2. 4 10 -3 e. V 2) ICHEP 2004, Beijing CNGS horns (Orsay) 2

1 CNGS beam construction at CERN on schedule 3 2 1 2 3 First 1 CNGS beam construction at CERN on schedule 3 2 1 2 3 First beam to Gran Sasso in May 2006 steel decay pipe installed 18 mm thick, 4. 5 m Ø, + 50 cm of concrete Vacuum leak test on full 998 m tube OK ICHEP 2004, Beijing Intensity upgrade (x 1. 5) under study 3

OPERA appearance detection e, - p, e, p, n, p, K. . . Emulsion OPERA appearance detection e, - p, e, p, n, p, K. . . Emulsion layers ECC technique used in discovery (DONUT-2000) ICHEP 2004, Beijing decay kink 10. 2 x 12. 7 x 7. 5 cm Target mass ~1. 8 Kton + film alignment < 1 m high modularity Film base CC events: detection of the Based on the Emulsion Cloud Chamber (ECC) technique: emulsions for tracking, high Z plates as target 1 mm Pb - - n t n m BR 17. 4 % h- nt (np 0) 49. 5 % e- nt ne 17. 8 % p- p+ p- nt (np 0) 15. 0 % Basic unit: ECC “Brick” 56 lead plates 57 emulsion films 10 X 0 n 8. 6 kg 4

OPERA bricks and electronic detectors 1775 tons target: 200 000 bricks ECC bricks alone OPERA bricks and electronic detectors 1775 tons target: 200 000 bricks ECC bricks alone can provide: - vertex and decay kink reconstruction - momentum measurement by MCS - p/ separation at low E by d. E/dx - energy measurement of em showers, identification of electrons 2 Super-M odules ~ 9 m Target sections: 31 vertical “walls” of bricks 31 scintillation X-Y Target Tracker planes 5 cm Trigger and localisation of n interaction 1 mm TEST experiment at CERN PS ICHEP 2004, Beijing Spectrometer sections: Muon ID, 22 RPC planes in dipolar magnet momentum, charge meas. 6 sections of Precision Trackers 5

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

OPERA search for , topologies (1) Pick up all tracks from the n interaction OPERA search for , topologies (1) Pick up all tracks from the n interaction on the most downward film Scanning 5 x 5 cm 2 for CC a film full surface for NC Long decays power kink (2) Scan back picked up tracks (3) confirm n interaction vertex; tracks stopped in 2 consecutive films (4) search for kink candidates (5) fully measure candidate events Pb Emulsion layers Plastic (not to scale) base Short decays kink > 20 mrad ( kink ) ~ 3 mrad I. P. Pb Impact Parameter > 5 to 20 m (along Pb plate) (I. P. ) = 0. 3 to 0. 6 m ICHEP 2004, Beijing 7

Status of OPERA construction SM 2 magnet complete in April 2005 Target planes support Status of OPERA construction SM 2 magnet complete in April 2005 Target planes support Target sections: installation starts September 2004 ICHEP 2004, Beijing Brick Manipulator System Spectrometer sections: installation started May 2003 SM 1 magnet complete June 2004 8

OPERA magnets Magnet 1: all 22 gaps filled with RPC June 2004 With Precision OPERA magnets Magnet 1: all 22 gaps filled with RPC June 2004 With Precision Tracker: Dp/p = 20 -25%, charge mis-Id 0. 3% ID > 95% (Target Tracker + PT) 5 cm Fe slabs x 12 x 2 Total magnet weight 1000 tons B= 1. 55 T slabs coil ICHEP 2004, Beijing base May 2004 9

OPERA in construction: summer 2004 July 2004 ICHEP 2004, Beijing 10 OPERA in construction: summer 2004 July 2004 ICHEP 2004, Beijing 10

Spectrometer RPC and Precision Tracker Nov 2003: 1 st plane of RPC installed Drift Spectrometer RPC and Precision Tracker Nov 2003: 1 st plane of RPC installed Drift tubes Tracker For 25% DP/P : x ~ 0. 5 mm, high e multi-hit prototype module 8 m 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 ICHEP 2004, Beijing 4 layers, 8 m tubes 38 mm Ø, 50 m wire Simplified version of ATLAS drift tubes Performance: • efficiency: 99. 1% • resolution: 300 μm Installation: spring 2005 11

Target Tracker and brick walls Construction of TT modules (64 strips) in progress: 8 Target Tracker and brick walls Construction of TT modules (64 strips) in progress: 8 modules/week Brick wall full height prototype (6. 7 m) Well above 5 p. e. / readout end X and Y planes, 6000 m 2 in total - Scintillator strips (6. 86 m x 2. 6 cm x 1 cm): AMCRYS-H (Kharkov) above 5 p. e. specifs. - Kuraray WLS fibers 1000 Ma. PMT Hamamatsu 64 -channels - Dedicated Front End electronics: gain correction auto-triggerable, threshold @ 1/5 p. e. - Ethernet DAQ cards Target installation at LNGS: September 2004 - December 2005 ICHEP 2004, Beijing 12

ECC brick components: emulsion films, lead Film production started April 2003 (~150 000 m ECC brick components: emulsion films, lead Film production started April 2003 (~150 000 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 1 mm thick 10 m - ready for prototype production at Goslar Co. - Pb/Ag/Al-Sn to replace Pb/Ca (compatibility with emulsions) ICHEP 2004, Beijing 13

Brick assembly Mechanical packaging adopted (long term tests): less fragile than vacuum packaging pressure Brick assembly 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 s 200 000 bricks 40 m B all /h A all h s pa y- b Lead handling Piling stations Packaging ICHEP 2004, Beijing BAM contracted Jan 2004 with Tecno-Cut (Swiss-Italian Co) • Delivery at LNGS: April 2005 Brick assembly: Sep 2005, 1 year Filling SM 1 March 2006 SM 2 September 2006 14

Brick manipulator system Porticoes Storage carrousel on each side of detector, to place platform Brick manipulator system Porticoes Storage carrousel 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 Installation at LNGS: April 2005, Start detector brick filling: Sep. 2005 ICHEP 2004, Beijing 15

Automatic scanning R&D in Nagoya and Europe ~ 2 mrad x ~ 0. 3 Automatic scanning R&D in Nagoya and Europe ~ 2 mrad x ~ 0. 3 m d = 2 - 1 Bari, Bern, Bologna, Lyon, Napoli, Neuchâtel, Roma, Salerno European station Dedicated hardware Hard coded algorithms 500 fps CMOS camera Commercial hardware Software algorithms Fast CCD camera (3 k frames/sec) Continuous movement of the X-Y stage S-UTS prototype at Nagoya ICHEP 2004, Beijing • European system: recent version working at 20 cm 2/hr/side (15 to install) • S-UTS system expected to reach similar performances (under completion) Scanning lab to be installed @LNGS 16

OPERA detection efficiencies Channels considered at CNGS approval time (1999) e (DIS+QE, long) 3. OPERA detection efficiencies Channels considered at CNGS approval time (1999) e (DIS+QE, long) 3. 0 2. 6 Overall efficiency e = 5. 6 DIS long t® e t® m t® h Total 2. 7 2. 4 2. 8 8. 0 QE long 2. 3 2. 5 3. 5 8. 3 DIS short 1. 3 0. 7 1. 3 Efficiencies include: BR, long/short, BFE, kink + kinematics cut, Id and connection Overall (weighted sum) 3. 4 2. 8 2. 9 9. 1 % e *BR 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%) ICHEP 2004, Beijing 17

Expected number of background events 5 years, nominal beam in red: possible BKGD reduction Expected number of background events 5 years, nominal beam in red: possible BKGD reduction Charm background e. 210 . 117. 010 . 007 . 116 h Total . 162 . 382 . 284 . 116 . 023 Large angle μ scattering Hadronic background Total per channel . 160 . 093. 210 . 117 . 093 . 116 . 209 . 219 . 123 . 278 . 276 . 707 . 516 Charm background : Being re-evaluated using new CHORUS data: charm production increase by 40% (larger Lc production), charm semileptonic BR down by 20%. In addition π/μ Id by d. E/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 X 5 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 ICHEP 2004, Beijing 18

 sensitivity Number of events in 5 years @ 4. 5 x 1019 pot sensitivity Number of events in 5 years @ 4. 5 x 1019 pot / year (. . . ): with CNGS beam upgrade (x 1. 5) signal 1. 9 x 10 -3 e. V 2 OPERA signal 2. 4 x 10 -3 e. V 2 BKGD 3. 0 x 10 -3 e. V 2 6. 6 (10. 0) 10. 5 (15. 8) 16. 4 (24. 6) 0. 7 (1. 1) 8. 0 (12. 1) 12. 8 (19. 2) 19. 9 (29. 9) 1. 0 (1. 5) 1. 775 tons BFE improved by 10% + 3 prong decay With possible BKGD 30% reduction 0. 8 (1. 2) ICHEP 2004, Beijing 19

Sensitivity versus Beam Intensity Opera with beam x 1. 5, possible e improvements and Sensitivity versus Beam Intensity Opera with beam x 1. 5, possible e improvements and BKGD reduction Opera with beam x 1. 5, no BKGD reduction Opera with beam x 2 (~equivalent) Opera nominal beam and half background Opera nominal Opera with beam x 3 SK 90% CL (L/E analysis) ICHEP 2004, Beijing 20

 e sensitivity Expected signal and backgrounds assuming 5 years data taking, nominal CNGS e sensitivity Expected signal and backgrounds assuming 5 years data taking, nominal CNGS beam and Dm 223=2. 5 x 10 -3 e. V 2, sin 22 23=1 13 signal e CC NC e. CC 9º 9. 3 4. 5 1. 0 5. 2 beam 18 8º 7. 4 4. 5 1. 0 5. 2 18 7º 5. 8 4. 6 1. 0 5. 2 18 5º 3. 0 4. 6 1. 0 5. 2 18 Efficiency 0. 31 0. 032 0. 34 x 10 -4 7. 0 x 10 -4 0. 082 simultaneous use of Evisible, Eelectron and missing Pt sin 22 13 limit 90% CL 0. 06 0. 05 (beam x 1. 5) 7. 1º 6. 4º ICHEP 2004, Beijing Sensitivity to 13 has a dependence on d. CP complementary to T 2 K 21

Conclusions - OPERA is looking for oscillations ( appearance) and e oscillations (measurement of Conclusions - OPERA is looking for oscillations ( appearance) and e oscillations (measurement of 13 ) 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 ICHEP 2004, Beijing 22