1. The CLEO-c Detector Steve Gray Cornell University BESIII Workshop January 13, 2004

2. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 2 New Era -> New Needs Need Quality Tracking AND Precision EM Calorimetery Large 93%  –Nearly hermetic Full-range Particle ID Simulate Alternatives Coordinate with Storage Ring Expect High Luminosity High Statistics Systematics Dominate Rare Decays Backgrounds Matter –Fakes –Feed-down –Combinatorics

3. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 3 1.5 T now,... 1.0T later 93% of 4   p /p = 0.35% @1GeV dE/dx: 5.7%  @minI 93% of 4   E /E = 2% @1GeV = 4% @100MeV Trigger: Tracks & Showers Pipelined Latency = 2.5  s Data Acquisition: Event size = 25kB Thruput < 6MB/s CLEO III -> CLEO-c 83% of 4   % Kaon ID with 0.2%  fake @0.9GeV 85% of 4  For p>1 GeV

4. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 4 CLEO III  (4S) Typical Hadronic Event 10 tracks 10 showers

5. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 5

6. BESIII WorkshopThe CLEO-c DetectorJanuary 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 – z=1 cm; =2/8 Thin Inner Tube –0.12% X 0 60:40 Helium- Propane

7. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 7

8. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 8 Drift Chamber Performance Avg. residual 85 m –Best 65 m MC agreement Momentum Resolution – p/p=0.7% at 5 GeV/c – p/p=0.3% at 1 GeV/c –MS limited < 1.5 GeV/c dE/dx resolution –5.7% at min Ionizing –K– sep. at low p Drift Distance (mm) Residual (  m) 04-48-8 50 100 150 DR3 All Layers

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

10. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 10 ZD – Inner Drift Chamber 6 stereo layers: –r=5.3 cm – 10.5 cm –12-15 o stereo angle –|cos  < 0.93 300, 10 mm cells 1% X 0,.8mm Al inner tube 60:40 Helium-Propane 20 m Au-W sense wires 110 m Au-Al field wires Outer Al-mylar skin

11. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 11 ZD Drawing

12. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 12

13. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 13 Tracking with ZD P (GeV/c)0.250.490.971.361.912.68 Z0 (  ) 806702684680672667  p/p (%) 0.32 0.350.390.450.56 ZD Calibration Underway –Residuals now < 200  Expect to outperform CLEO-c/CESR Project Description

14. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 14 Cosmic Ray in ZD June 7, 2003

15. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 15 CLEO-c Event in ZD June 7, 2003

16. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 16 RICH Detector LiF Radiators –Flat and sawtooth –UV photons (135-160 nm) N 2 expansion volume MWPC photo-detectors –TEA & CH 4   LiF radiator K/ 

17. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 17 RICH Detector

18. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 18

19. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 19 Resolution & Performance CLEO III data D->K without & with RICH cuts. 80% eff, 8:1 bkg suppression K- Separation (Chisq Difference)

20. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 20 RICH Performance Designed for B decay Excellent for D decay K –  separation Measured in data D*  D 0  + ; D 0  K -  + High efficiency Low  fake rates Combine with dE/dx CLEO-c B physics Kaon eff = 0.8 Kaon eff = 0.85 Kaon eff = 0.9

21. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 21 CsI Calorimeter Projective Barrel Endcaps 4 photodiode readout Triple range ADCs Excellent –Photon finding –Electron ID –  0 &  reconstruction

22. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 22 CLEO CsI at a Glance ~7800 CsI(Tl) crystals ~ 5530 cm 3 (16X 0 ) 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 WorkshopThe CLEO-c DetectorJanuary 13, 2004 23 CLEO II -> CLEO III Barrel unchanged TF removed, RICH inserted DR lengthened & narrowed Endplate material thinned Endcap repackaged Pushed back ~7 cm

24. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 24 CsI for CLEO III & CLEO-c Barrel unchanged from CLEO II –But DR/Particle ID changes increase minimally obstructed barrel from 70% to 80% of 4 – “Good Barrel” is 14% bigger than CLEO II’s Endcaps repackaged for new I.R. superconducting quadrupoles – Thinner DR Endplate & better support design make less material in front than CLEO II – Only ~40%X 0, about 30% of CLEO II material – “Good Endcap” coverage |cos| = 0.85 to 0.93 Quality solid angle ~25% > than CLEO II New digitizing electronics

25. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 25 CsI Performance

26. BESIII WorkshopThe CLEO-c DetectorJanuary 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 WorkshopThe CLEO-c DetectorJanuary 13, 2004 27  ’  X,    +  - CLEO-c Muon System

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

29. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 29 Data Acquisition VME & FastBus front ends Designed for 1 kHz & 4 MB/sec Achieved 500 Hz & 6 MB/sec Several upgrades completed A few remain for Spring 2004

30. BESIII WorkshopThe CLEO-c DetectorJanuary 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 WorkshopThe CLEO-c DetectorJanuary 13, 2004 31 Credits Calorimetry - Brian Heltsley DAQ - Tim Wilkson Tracking - Karl Ecklund, Dan Peterson Trigger - Topher Caulfield

32. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 32  ’   +  - ;   e + e -

33. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 33 CLEO-c Event Picture D +   +  -

34. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 34 CLEO-c Event Picture D 0  

35. BESIII WorkshopThe CLEO-c DetectorJanuary 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 Size of CLEO: 120–220 Collaborators

36. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 36 CESR at Cornell

37. BESIII WorkshopThe CLEO-c DetectorJanuary 13, 2004 37 CLEO III Running for CLEO-c