1. DT calibration status A. Vilela Pereira for the DT calibration team (Università degli Studi di Torino & INFN Torino) Muon Barrel Workshop – July 7 2010

2. Outline 07/07/2010DT Calibration - Muon Barrel Workshop2 Highlights from CMS Week Collision events selection Computation of tTrig DB from time boxes Residuals and tTrig corrections

3. Status from CMS Week 07/07/2010DT Calibration - Muon Barrel Workshop3 Possible to start computing tTrig with SL granularity MinimimBias GOODCOLL Skim Mu DtCalib ALCARECO Dedicated DT calibration ALCARECO data set however suffers from large background from cosmics

4. Outline 07/07/2010DT Calibration - Muon Barrel Workshop4 Highlights from CMS Week Collision events selection Effect on residuals and segment t0 distributions Computation of tTrig DB from time boxes Residuals and tTrig corrections

5. Datasets and collision selection 07/07/2010DT Calibration - Muon Barrel Workshop5 /MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO /Commissioning/Run2010A-MuonDPG_skim-May27thSkim_v2/RAW-RECO /Mu/Run2010A-DtCalib-*/ALCARECO DT activity + muon selection, BPTX + cleaning of scraping events and beam backgrounds On RECO datasets required primary vertex On ALCARECO datasets required BSC coincidence (but no primary vertex, whose collection is not in the event content)

6. Residuals – Collision selection 07/07/2010DT Calibration - Muon Barrel Workshop6 MB1MB2 MB3 MB4 Wheel 0 Sector 4 SL1 N.B. Residuals computed using current tTrig table in Global tag Sub-sample of events passing collision criteria

7. Residuals – Collision selection 07/07/2010DT Calibration - Muon Barrel Workshop7 MB1MB2 MB3MB4 Wheel 0 Sector 7 SL1 Vetical sectors less dominated by cosmics

8. Segment t0 – Collision selection 07/07/2010DT Calibration - Muon Barrel Workshop8 MB1MB2 MB3 MB4 Wheel 0 Sector 4 – RPhi segment

9. Segment t0 – Collision selection 07/07/2010DT Calibration - Muon Barrel Workshop9 MB1MB2 MB3MB4 Wheel 0 Sector 7 – RPhi segment

10. Outline 07/07/2010DT Calibration - Muon Barrel Workshop10 Highlights from CMS Week Collision events selection Computation of tTrig DB from time boxes Residuals and tTrig corrections

11. Time boxes 07/07/2010DT Calibration - Muon Barrel Workshop11 /MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO MB1MB2MB3 MB4 Statistics reduced as one goes further from IP Somewhat increased noise in Minimum bias data set

12. Reminder of tTrig computation 07/07/2010DT Calibration - Muon Barrel Workshop12 i.Inter-channel calibration (t 0 ): per wire relative times from test pulses ii.t trig : Time pedestal from fit to rising-edge of time box: Gives t mean &  (t mean ) Additional k-Factor needed to tune the final time pedestal: Note: k-Factor also in tTrig DB (per SL): t trig = t mean + k x  tTrig DB t mean  (t mean ) k-Factor

13. tTrig workflow 07/07/2010DT Calibration - Muon Barrel Workshop13 DTTTrigCorrection DTTTrigResidual Correction … t mean,  (t mean ) t trig = t mean + k x  t mean,  (t mean ), k-Factor tTrig DB t mean  (t mean ) k-Factor t trig pedestals from fit to rising-edge of time box, with super-layer granularity Uncertainty in fitting of the time box requires a further correction to remove (reduce) bias in residuals

14. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop14 SL1 SL3 SL2 /MinimumBias/Commissioning10-Muon_skim-May27thSkim_v5/RAW-RECO tTrig (ns) N.B. tTrig from current DB ~322 ns

15. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop15 SL1 SL3 SL2 /Mu/Run2010A-DtCalib-May27thReReco_v2/ALCARECO SL1 tTrig (ns) tTrig sigma (ns) tTrig (ns)

16. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop16 SL1 SL3 SL2 tTrig (ns) Wh0 tTrig values consistent when running on different datasets and different collision event selection

17. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop17 SL1 SL3 SL2 tTrig (ns) Wh2 Some discrepancy in Wheels +/- 2 in MB1, as shown before during CMS Week Effect could be related to different vDrift in this chamber (constant in DB)

18. Residuals from calculated tTrig db 07/07/2010DT Calibration - Muon Barrel Workshop18 Wh0 Residuals within ~100 μm Remaining bias expected to be reduced by using effective vDrift procedure (see past presentations)

19. Effect of residual correction 07/07/2010DT Calibration - Muon Barrel Workshop19 Wh0 t trig = t mean + k x 

20. Summary & Next steps 07/07/2010DT Calibration - Muon Barrel Workshop20 First results from tTrig from collisions. Consistent results from previously estimated values from cosmics. Collision selection studied  should finalize criteria and include either in the DT ALCARECO production or leave it in the calibration workflow (possibly updating ALCARECO event content). Automatic tTrig calibration procedure has been updated and used regularly. tTrig DB could be loaded for tests. Results for more recent runs to be produced soon.

21. Backup 07/07/2010DT Calibration - Muon Barrel Workshop21

22. Segment t0 – Collision selection 07/07/2010DT Calibration - Muon Barrel Workshop22 MB1MB2 MB3 Wheel 0 Sector 4 – RZ segment

23. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop23 SL1 SL3 SL2 tTrig (ns) Wh-2

24. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop24 SL1 SL3 SL2 tTrig (ns) Wh-1

25. tTrig from calibration workflow 07/07/2010DT Calibration - Muon Barrel Workshop25 SL1 SL3 SL2 tTrig (ns) Wh1

26. Residuals from new tTrig db 07/07/2010DT Calibration - Muon Barrel Workshop26 Wh-2 Wh-1

27. Residuals from new tTrig db 07/07/2010DT Calibration - Muon Barrel Workshop27 Wh1 Wh2

28. tTrig corrections 07/07/2010DT Calibration - Muon Barrel Workshop28 DTTTrigCorrection DTTTrigMatchRPhi DTTTrigResidual Correction DTTTrigT0Seg Correction … t mean,  (t mean ) t trig = t mean + k x  t mean,  (t mean ), k-Factor Implemented series of “corrections” on top of original DB: i.Match time pedestal values for two R-  SL’s ii.Automatic tuning of k-Factor iii.Fill missing values, etc. tTrig DB t mean  (t mean ) k-Factor

29. tTrig calibration 07/07/2010DT Calibration - Muon Barrel Workshop29 tTrig correction I tTrig correction II vDrift DTTTrigMatchRPhi DTTTrigResidual Correction DTTTrigT0Seg Correction … t mean,  (t mean ) tTrig DB t mean,  (t mean ), k-Factor