1. Pixel Results from CRAFT09 U. Langenegger (PSI), G. Giurgiu (JHU) Pixel General Meeting November 10, 2009

2. 2 CRAFT09 Analyses - Gain calibration + Validation – R. Rougny (Antwerpen), U. Langenegger (PSI) - Pixel hit efficiency - L. Mucibello, R. Rougny, N. van Remortel (Antwerpen) - Pixel hit resolution – K. Ulmer (Colorado) - BPIX Lorentz angle – M. Ivova, V. Chiochia (Zurich) - FPIX Lorentz angle – A. Kumar, A. Godshalk, A. Kharchilava (Buffalo) - Data/MC comparison – A. Jaeger, V. Chiochia (Zurich), M.Swartz (JHU) - All analyses done with most recent CRAFT09 reprocessing /Cosmics/CRAFT09-TrackingPointing-CRAFT09_R_V4_CosmicsSeq_v1/RAW-RECO

3. 3 Gain Calibration R. Rougny (Antwerpen), U. Langenegger (PSI) - Pixel thresholds minimized before CRAFT09 → procedure led to significant fraction of negative BPIX pedestals - After CRAFT09, detector settings changed to fix negative pedestals (Ben Kreis, D. Kotlinski) → new gain calibration taken (run 117680) → fraction of negative pedestals indeed negligible in new calibration: BPIX FPIX

4. 4 Gain Calibration Validation U. Langenegger (PSI), R.Rougny (Antwerpen) - Analyze post-CRAFT09 data to validate new gain calibration CRAFT09 data - Fraction of post-CRAFT09 data - No problems seen Runs 119226 119094 119090 119088 119079 119022 119017 118969 118878 118762 118621

5. 5 In http://www.phys.ethz.ch/~ursl/cms/091110/ you can find a higher statistics version of the CRAFT09-II gain calibration validation. This is still without the SP skim. CRAFT09-II ---------- cluster charge: http://www.phys.ethz.ch/~ursl/cms/091110/craft09-II-clusterCharge.ps BPIX Landau+Gauss: http://www.phys.ethz.ch/~ursl/cms/091110/craft09-II-bpix.ps FPIX Landau+Gauss: http://www.phys.ethz.ch/~ursl/cms/091110/craft09-II-fpix.ps reprocessed CRAFT09 SP skim --------------------------- cluster charge: http://www.phys.ethz.ch/~ursl/cms/091110/reprocessed-sp-data-clusterCharge.ps BPIX Landau+Gauss: http://www.phys.ethz.ch/~ursl/cms/091110/reprocessed-sp-data-bpix.ps FPIX Landau+Gauss: http://www.phys.ethz.ch/~ursl/cms/091110/reprocessed-sp-data-fpix.ps The MPV have come down a bit in both BPIX and FPIX, the effect of the slightly lowered gains, visible in the overlayed offline payload comparison for the new and previous gain calibration runs http://www.phys.ethz.ch/~ursl/cms/091110/gains-108062-117680.png The relative width has decreased (increased) slightly for the BPIX (FPIX). The gain calibration looks good Gain Calibration Validation U. Langenegger (PSI)

6. 6 Data / MC Comparison A. Jaeger, V. Chiochia (Zurich)

7. 7 Data / MC Comparison – Cluster Charge A. Jaeger, V. Chiochia (Zurich) - Fair agreement between data and MC - Disagreement at low charge could be explained by lower thresholds in MC than in data - Andreas will produce MC with higher thresholds which match data barrel

8. 8 Data / MC Comparison – Pixel Charrge A. Jaeger, V. Chiochia (Zurich) barrel

9. 9 Data / MC Comparison – Pixel Hit Probability A. Jaeger, V. Chiochia (Zurich) - Pixel hit probability calculated as chi2 probability of the matching between the observed cluster shape and the expected template - Fair qualitative agreement between data and MC → important test since we plan to use pixel probability to improve tracking (remove bad hits, split merged clusters…) - Work in progress - re-digitize MC with higher thresholds to match MC - optimize phase space to emulate collisions better (~4000 electrons) barrel

10. 10 Pixel Hit Efficiency L. Mucibello, R. Rougny, N. van Remortel (Antwerpen)

11. 11 Pixel Hit Efficiency L. Mucibello, R. Rougny, N. van Remortel (Antwerpen) Layer 1 Layer 2 Layer 3 White boxes = known bad modules low statistics Eff = N valid / (N valid + N missing ) Pixel sensor efficiency ~ 98.3 – 98.5% - Will investigate pixel efficiency with strip seeded tracks to avoid biases in efficiency

12. 12 Pixel Hit Resolution K. Ulmer (Colorado) - Pixel hit resolution measured in CRAFT09 using the “double difference” method - Compare measured resolution with predicted errors from template based cluster parameter estimator (CPETemplate) - Resolution in microns : reprocessed original processing measured predicted measured predicted X 18 ± 1 15 ± 1 19 ± 3 15 ± 1 Y 26 ± 1 23 ± 1 32 ± 2 25 ± 2 - Measured resolution about 10-20% worse than predicted by CPE - Will repeat measurements with much better statistics with collisions - Will correct CPE predicted errors to match observed resolution

13. 13 BPIX Lorentz Angle – Cluster Size Method M. Ivova, V. Chiochia (Zurich) E - Good agreement LA measured in latest and first processing as well as with the PIXELAV Simulation cot(  ) min = -0.408 +/- 0.002 – latest CRAFT09 reprocessing cot(  ) min = -0.405 +/- 0.003 – first CRAFT09 processing cot(  ) min = -0.397 +/- 0.003 – PIXELAV simulation (M. Swartz) B field ON B field OFF LA consistent with zero within 2   Lorentz ≈ 22°

14. 14 FPIX Lorentz Angle – Cluster Size Method A. Kumar, A. Godshalk, A. Kharchilava (Buffalo) - Good agreement LA measured in latest and first processing as well as with the PIXELAV Simulation cot(  ) min = -0.084 +/- 0.008 – first CRAFT09 reprocessing cot(  ) min = -0.080 +/- 0.005 – latest CRAFT09 processing cot(  ) min = -0.081 +/- 0.003 – PIXELAV simulation (M. Swartz)  Lorentz ≈ 5° LA consistent with zero B field ON B field OFF

15. 15 FPIX Lorentz Angle – Grazing Angle Method A. Kumar, A. Godshalk, A. Kharchilava (Buffalo) - Buffalo group also measured FPIX LA using grazing angle method in CRAFT08 and got good agreement with cluster size method → nice proof of principle 3.75° ± 0.41° - grazing angle 3.95° ± 0.39° - cluster size - This is important since with collisions cluster size method is not adequate - With collisions grazing angle method will be used for BPIX - For FPIX neither grazing angle nor cluster size are optimal with collision tracks → might have to rely on cosmics only Depth (  m ) Avg. Drift ( m m)

16. 16 Conclusion - Gain calibration in place and validated with post CRAFT09 data - Lorentz angles measured and in agreement with previous processing and with PIXELAV simulation - Pixel sensor efficiency ~98.5% - Next step: use strip seeded tracks to avoid biases - Reasonable data/MC agreement when collision like cosmic tracks selected but some cosmic specific effects not simulated - Pixel hit resolution within 10-20% from expectation - Will repeat with collisions and adjust predicted errors if needed

17. 17 Backup Slides

18. 18 Gain Calibration Validation U. Langenegger (PSI), R.Rougny (Antverpen)

19. 19 CRAFT09 data - Fraction of post-CRAFT09 data - No problems seen Gain Calibration Validation U. Langenegger (PSI), R.Rougny (Antverpen)

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