1. LHCb Status Report: LHCb Status Report: B-Physics with Tracking SAC Review Meeting April 20, 2007 Marcel Merk for the B-physics group Contents: Outer Tracker Vertex Locator Software

2. 2 LHCb detector  10 mrad bb bb 250 mrad

3. 3  Silicon strip detector  Reconstruct primary and secondary vertices  Tracking, use R-Phi geometry  Used in L1 trigger  Pile-Up Trigger in L0 The VErtex LOcator in LHCb 

4. 4  Straw tube detector  Momentum determination with TT and magnet  Tracking, use XUVX geometry  3 OT stations: T1, T2, T3 The Outer Tracker in LHCb 

5. 5 The Experiment Velo OT

6. 6 Outer Tracker - Collaboration J. Amoraal, R. Arink, H. Band, Th.S. Bauer, A. Berkien, L. Ceelie, G. Fanizzi, F. Jansen, B. M’charek, A. Pellegrino, O. v. Petten, T. du Pree, J. Rovekamp, F. Schimmel, H. Schuijlenburg, E. Simioni, T. Sluijk, J. Spelt, H.Terrier, N. Tuning, A. Zwart The NIKHEF OT group: Dortmund, Heidelberg, Warsaw, Cracow, Bejing, VU, Nikhef: NIKHEF provides OT project leader Nikhef Activities: Mass production: mechanics & electronics Infrastructure: frames and support bridge Installation & quality Assurance Irradiation studies

7. 7 The Outer Tracker C-frame OT Bridge Table & Cable Trays Modules

8. 8 OT Modules and Performance One large module:  34 x 490 cm 2  4 x 64 = 256 channels Resolution: σ  200 µm Plateau Efficiency: ε  100%

9. 9 Detector Installation - completed Front-End Boxes LV,HV, ECS/TFC.. Cooling and Gas Detector Modules module Δz [mm] Mechanical installation precision: z-coordinate : deviation within 1 mm T2-Q02-XU X-layer

10. 10 Electronics First C-frame equipped with FE boxes  HV board: 900 of 2000 tested and assembled Problem with alignment holes  ASDBLR amplifier board: All 4000 boards produced  OTIS TDC board: Total 2000 boards needed Bonding completed! (Major task..)  GOL AUX board: Production & Test completed

11. 11 Quality Assurance  Tests C-frames LV, HV, Data Fibers, Gas  Tests detector modules: Gast tightness, dark currents, signals R.A. sources  Tests Front End Amplifier threshold uniformities Time resolution  Commissioning Noise measurement Testpulse tests: Linearity, stability, resolution, uniformity

12. 12 Module 61 Channel nr. Pulse height (mV) Tested in the pit in the C cage 4 “dead” wires out of 6867 tested Example QA : Straw Response to 55 Fe

13. 6 April 200613 Outer Tracker Irradiation Studies Channel Pos (cm) Gain loss seen in production modules  Damage upstream the gas flow Damage only in low intensity region!  Electron microscope: isolating carbon layer

14. 6 April 200614 Outer Tracker Irradiation Studies Channel Pos (cm) Suspect out-gassing effect:  Flushing of all modules started  Warming of modules to force outgassing  HV processing cures and part. Prevents Gain loss seen in production modules  Damage upstream the gas flow Damage only in low intensity region!  Electron microscope: isolating carbon layer Flushing  Rel gain  Flush Time (days) 2 nd HV training 1 st HV training 3 rd HV training  Relative Gain  Irradiation Time (hours)

15. 15 Velo - Collaboration The NIKHEF Velo group: NIKHEF provides Velo deputy projectleader Nikhef Activities: Mechanics + RF Motion Control Vacuum control CO 2 Cooling Pile-Up trigger Heidelberg, MPI, Liverpool, Glasgow, CERN, Lausanne, Syracuse, VU, Nikhef M. Beuzekom, J. v/d Brand, M. Doets, P. de Groen, E. Jans, L. Jansen, T. Ketel, A. Keune, M. Kraan, F. Mul, B. Munneke, A. Papadelis, E. Roeland, F. Schimmel, A. Van Lysebetten, B. Verlaat, T. Versloot, H. de Vries, L. Wiggers

16. 16 VErtex LOcator Silicon sensors Vacuum vessel rf-box rectangular bellows exit window wake field suppressor ~1 m kaptons The Vertex Locator

17. 17 VELO Detector half

18. 18 The Detector Vacuum box (“RF Box”) Thin, leak-tight corrugated RF foil between sensors and beam super plastic pressing of 300  m Al foil with hot gas welding into a vacuum tight box 30 mm

19. 19 The Detector Vacuum box (“RF-box”)  Leak rate between beam and detector volumes determined to be : 2.4x10 -5 mbar.l/s @ 1.6 mbar He Saturation NEG coating during installation Other solution considered for 2009 run   p < 5 mbar at all times!

20. 20 Vacuum  During pumpdown and venting:  p < 5 mbar between beam-vacuum and detector-vacuum p [mbar] 10 time p beam -p det. [mbar] 0 400 800 1200 0 4 -4

21. 21 How the beam sees the Velo

22. 22 Positioning the Detector in the beam: Motion Control parking position closed position  motion control implemented in a PLC.  software and hardware limits.  reproducibility < 10  m  UPS system  3 d.o.f.: XR, XL and Y Allowed regions: -5.0 < X < 29.0 mm for -1.0 < Y < 1.0 mm -4.7 < Y < 4.7 mm for X < 5.0 mm

23. 23 0 15 -1530 -30 [mm] rf-foil VELO open 0. half-open VELO tracking LHC-beams crossing VELO closed 15 -15 30 -30 -45 45 [mm]

24. 24 Cooling system and cooling plant  CO 2 part ready  Next steps: Cabling, PLC control, insulation, testing  Delivery at CERN by June Flexible in and outlet lines Capillary and T-Sensor channel Cooling blocks PT100 cables PT100 Interface board Vapor outlet Liquid inlet Cooling vacuum feed trough

25. 25 Pile-Up trigger  4 Upstream modules with R-sensors  Uses digital readout of Beetle chips  vetoes BXs with multiple PV’s 4 PU-hybrids 8 optical Tx-boards 4 vertex processing boards 1 output board L0DU 125 Gb/s under construction 4 PU-hybrids 8 optical Tx-boards 4 vertex processing boards 1 output board L0DU 125 Gb/s under construction

26. 26 Software - Overview J. Amoraal, Th. Bauer, E. Bos, H.J. Bulten, S. Cohen, L. Hooft van Huysduyn, B. M’charek, M. Merk, J. Nardulli, A. Papadelis, G. Raven, T. du Pree, N. Tuning, P Vankov, G. Ybeles Smit, The NIKHEF Software group: NIKHEF has convenorship of: - Proper time and mixing group - Track fitting group

27. 27 Physics Motivation  CKM Metrology: 1.A mix : B s → D s  m s A CP : B s → D s K  s 2.A CP : B s → J/  s  Rare Decays: 1.Br: B (s) →  2.A fb: B 0 →K * , b →s  Looking for effects of new physics in the flavour sector: b s s b “Box” These subjects exploit LHCb advantages over other experiments Well matched to our activities: i.OT construction ii.VELO construction iii.Track reconstruction “Penguin” b s 4 “teams”: each with 1-2 staff, 1 postdoc, 2-3 students

28. 28 Result of track finding Typical event display: Red = measurements (hits) Blue = all reconstructed tracks Efficiency vs p :Ghost rate vs p T : Eff = 94% (p > 10 GeV) Ghost rate = 3% (for p T > 0.5 GeV) VELO TT T1 T2 T3 On average: 26 long tracks 11 upstream tracks 4 downstream tracks 5 T tracks 26 VELO tracks 20  50 hits assigned to a long track: 98.7% correctly assigned Ghosts: Negligible effect on b decay reconstruction

29. 29 Kalman Track Fit  Reconstruct tracks including multiple scattering.  Main advantage: correct covariance matrix for track parameters.  Implemented tracking in misaligned geometry. z Impact parameter pull distribution:  = 1.0 Momentum pull distribution:  = 1.2

30. 30 Impact Parameter and Momentum Resolution  IP = 14  + 35  /p T parameter resolution Impact parameter resolution → 1/p t (1/GeV) 1/p T spectrum B tracks  p/p = 0.35% – 0.55% p spectrum B tracks Momentum resolution → Momentum (GeV)

31. 31 Mass and Lifetime resolution B s  D s  proper time resolution  t ~ 40 fs Example: B s ->D s K/  DsDs BsBs KK KK  ,K   47  m 144  m 440  m Mass and lifetime resolutions Are typically a factor 2-3 better than ATLAS/CMS Mass resolution: ~14 MeV Proper time resolution: ~40 fs

32. 32 Theses b-physics  Theses on LHCb: (2001) N. Zaitsev Pile-up and B s →J  (2002) R. v.d. Eijk OT and tracking (2003) R. Hierck Tracking and B s →D s K/  (2004) N. v. Bakel Velo and B s mixing (2005) S. Klous Velo and B s →J/  (2005) J. v. Tilburg Tracking and B s →D s K/  (2006) B. Hommels Tracking and Trigger »  Theses on Hera-B: (2002) M. Bruinsma J/  in pA (2002) W. Hulsbergen Track reconstruction (2003) M. Mevius B cross-section (2005) H. Wahlberg B cross-section (2006) A. Sbrizzi B X-section & pentaquark  Thesis on Babar: (2006) M.Baak CKM angle gamma

33. 33 Summary  Outer Tracker Detector installed Cabling ready Front end being tested and installed (tight schedule!) Commissioning ongoing Irradiation studies ongoing with high priority  Velo Vacuum vessel installed Vacuum control commissioned: leak detected in RF boxes Motion control commissioned Cooling infrastructure being installed in summer  Software Reconstruction framework ready Tracking algorithms being finalized Alignment algorithms being implemented Looking forward to data (hopefully already in 2007…)