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The CLEO-c Detector

BESIII Workshop. The CLEO-c Detector. January 13, 2004 2. New Era -> New Needs. NeedQuality Tracking ANDPrecision EM CalorimeteryLarge 93% DWNearly hermeticFull-range Particle IDSimulate AlternativesCoordinate withStorage Ring. ExpectHigh LuminosityHigh StatisticsSystematics DominateRare DecaysBackgrounds MatterFakesFeed-downCombinatorics.

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The CLEO-c Detector

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    1. The CLEO-c Detector Steve Gray Cornell University BESIII Workshop January 13, 2004 Both BES and CLEO have a great tradition in the Physics of Heavy Quarks. Both groups, with the crucial contribution of their accelerator partners, are making big changes to reach new physics previously inaccessible.Both BES and CLEO have a great tradition in the Physics of Heavy Quarks. Both groups, with the crucial contribution of their accelerator partners, are making big changes to reach new physics previously inaccessible.

    2. BESIII Workshop The CLEO-c Detector January 13, 2004 2 New Era -> New Needs Need Quality Tracking AND Precision EM Calorimetery Large 93% DW Nearly hermetic Full-range Particle ID Simulate Alternatives Coordinate with Storage Ring New era of high luminosity and high statistics data. Systematics will now become important. Hermeticity improves efficiency, reduces feed-down backgrounds, reduces extrapolations and model dependencies. Particle ID reduces fake and combinatorial backgrounds. Low mass detectors and supports preserve precious resolution. New Era means new Needs New era of high luminosity and high statistics data. Systematics will now become important. Hermeticity improves efficiency, reduces feed-down backgrounds, reduces extrapolations and model dependencies. Particle ID reduces fake and combinatorial backgrounds. Low mass detectors and supports preserve precious resolution. New Era means new Needs

    3. BESIII Workshop The CLEO-c Detector January 13, 2004 3

    4. BESIII Workshop The CLEO-c Detector January 13, 2004 4

    5. BESIII Workshop The CLEO-c Detector January 13, 2004 5

    6. BESIII Workshop The CLEO-c Detector January 13, 2004 6 Drift Chamber Coordinated with IR 9796 sense wires 14 mm square cell 16 inner axial layers 31 stereo layers Outer cathode segmentation Dz=1 cm; Df=2p/8 Thin Inner Tube 0.12% X0 60:40 Helium-Propane

    7. BESIII Workshop The CLEO-c Detector January 13, 2004 7

    8. BESIII Workshop The CLEO-c Detector January 13, 2004 8 Drift Chamber Performance Avg. residual 85 mm Best 65 mm MC agreement Momentum Resolution dp/p=0.7% at 5 GeV/c dp/p=0.3% at 1 GeV/c MS limited < 1.5 GeV/c dE/dx resolution 5.7% at min Ionizing Kp sep. at low p

    9. BESIII Workshop The CLEO-c Detector January 13, 2004 9 ZD Inner Drift Chamber Charm -> lower momentum spectrum Multiple scattering limited dp/p No vertexing needed Replace silicon with low-mass Z tracker Similar mass resolution More layers - better track recognition

    10. BESIII Workshop The CLEO-c Detector January 13, 2004 10 ZD Inner Drift Chamber 6 stereo layers: r=5.3 cm 10.5 cm 12-15o stereo angle |cos q| < 0.93 300, 10 mm cells 1% X0, .8mm Al inner tube 60:40 Helium-Propane 20 mm Au-W sense wires 110 mm Au-Al field wires Outer Al-mylar skin

    11. BESIII Workshop The CLEO-c Detector January 13, 2004 11

    12. BESIII Workshop The CLEO-c Detector January 13, 2004 12

    13. BESIII Workshop The CLEO-c Detector January 13, 2004 13 Tracking with ZD

    14. BESIII Workshop The CLEO-c Detector January 13, 2004 14

    15. BESIII Workshop The CLEO-c Detector January 13, 2004 15

    16. BESIII Workshop The CLEO-c Detector January 13, 2004 16 RICH Detector LiF Radiators Flat and sawtooth UV photons (135-160 nm) N2 expansion volume MWPC photo-detectors TEA & CH4

    17. BESIII Workshop The CLEO-c Detector January 13, 2004 17 RICH Detector

    18. BESIII Workshop The CLEO-c Detector January 13, 2004 18

    19. BESIII Workshop The CLEO-c Detector January 13, 2004 19 Resolution & Performance

    20. BESIII Workshop The CLEO-c Detector January 13, 2004 20 RICH Performance Designed for B decay Excellent for D decay K p separation Measured in data D*?D0p+; D0? K-p+ High efficiency Low p fake rates Combine with dE/dx

    21. BESIII Workshop The CLEO-c Detector January 13, 2004 21 CsI Calorimeter Projective Barrel Endcaps 4 photodiode readout Triple range ADCs Excellent Photon finding Electron ID p0 & h reconstruction

    22. BESIII Workshop The CLEO-c Detector January 13, 2004 22 CLEO CsI at a Glance ~7800 CsI(Tl) crystals ~5?5?30 cm3 (16X0) 4 photodiode readout w/local preamps 229 crystals have 1 turned off (too noisy) 10 crystals have 2 turned off (6 in endcap) 0 have 3 or 4 turned off. ~7 dead crystals in CLEO III (all in endcaps, 5 near inner or outer radii) External summation/pulse shaping & TDC Total noise per crystal is ~0.5 MeV incoherent & ~0.2 MeV coherent Light output losses calibrate away

    23. BESIII Workshop The CLEO-c Detector January 13, 2004 23 CLEO II -> CLEO III My words against the BESII plan for 10 cm of TOF scintillator were probably at least somewhat off base. CLEO II survived with 5cm scintillator. I think this is about 12% Rad leng/5 cm. Adding another 12cm is significantly worse than the first 12 cm because showers spread not only due to showering but also due to the magnetic field effect. The negative effect will most likely materialize as a low momentum efficiency loss (bigger low-side tails from lost energy) and signal/noise (because the resolution is worse, one has to accept a bigger mass window for pi0's). I guess the key is to have proven that the physics goals are not compromised with GEANT-MC tests. I would think this would be very important. Brian My words against the BESII plan for 10 cm of TOF scintillator were probably at least somewhat off base. CLEO II survived with 5cm scintillator. I think this is about 12% Rad leng/5 cm. Adding another 12cm is significantly worse than the first 12 cm because showers spread not only due to showering but also due to the magnetic field effect. The negative effect will most likely materialize as a low momentum efficiency loss (bigger low-side tails from lost energy) and signal/noise (because the resolution is worse, one has to accept a bigger mass window for pi0's). I guess the key is to have proven that the physics goals are not compromised with GEANT-MC tests. I would think this would be very important. Brian

    24. BESIII Workshop The CLEO-c Detector January 13, 2004 24 CsI for CLEO III & CLEO-c What is actual Endcap material ratio? What do we know about the effect of material? TOF->RICH and reduced DR endplate? Why did we change electronics?What is actual Endcap material ratio? What do we know about the effect of material? TOF->RICH and reduced DR endplate? Why did we change electronics?

    25. BESIII Workshop The CLEO-c Detector January 13, 2004 25 CsI Performance

    26. BESIII Workshop The CLEO-c Detector January 13, 2004 26 Lessons from the Calorimeter Endcaps reconfigured for CLEO III Many crystals had lost signal with age Glue joint had opened up Endcap crystals reglued Unable to fix barrel glue joints Material matters Much improved Endcap performance

    27. BESIII Workshop The CLEO-c Detector January 13, 2004 27

    28. BESIII Workshop The CLEO-c Detector January 13, 2004 28 Trigger Programmable (FPGA), Pipelined Track and CsI cluster primitives: Tracks (pt>150 MeV/c) Low, Med, High shower clusters Combine to define triggers, e.g. >2 tracks + low shower e >99% for hadronic events For CLEO-c Reduce med & high thresholds Add new neutral-only triggers Implemented Tile Sharing

    29. BESIII Workshop The CLEO-c Detector January 13, 2004 29 Data Acquisition Checkthis Greg and/or TimCheckthis Greg and/or Tim

    30. BESIII Workshop The CLEO-c Detector January 13, 2004 30 Summary New era of high luminosity makes new demands on the detector. The CLEO-c Detector is state of the art, understood at a precision level, now taking data in the charm region.

    31. BESIII Workshop The CLEO-c Detector January 13, 2004 31 Credits Calorimetry - Brian Heltsley DAQ - Tim Wilkson Tracking - Karl Ecklund, Dan Peterson Trigger - Topher Caulfield

    32. BESIII Workshop The CLEO-c Detector January 13, 2004 32

    33. BESIII Workshop The CLEO-c Detector January 13, 2004 33

    34. BESIII Workshop The CLEO-c Detector January 13, 2004 34

    35. BESIII Workshop The CLEO-c Detector January 13, 2004 35 CLEO History CLEO I (1979-89) CLEO II (1989-95) CsI calorimeter CLEO II.V (1995-99) Silicon Vertex Detector CLEO III (2000-03) RICH Particle ID New IR & tracking: Silicon, Drift Chamber CLEO-c (2003-??) Silicon replaced by ZD inner drift chamber

    36. BESIII Workshop The CLEO-c Detector January 13, 2004 36

    37. BESIII Workshop The CLEO-c Detector January 13, 2004 37 CLEO III Running for CLEO-c

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