1. InDet Tracking Performance Stephen Haywood RAL

2. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 2 Stephen Haywood Overview  Introduction  Performance presented in the ATLAS Detector Paper  First Data

3. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 3 Stephen Haywood Introduction Inner Detector Tracking Performance: Understand, Monitor and Optimise the ID performance. Inner Detector Tracking Performance is a "forum" for bringing together various groups: ID Software Physics and Combined Performance Working Groups Validation, ID Alignment and Calibration, Data Prep, etc See TWiki: InDetTrackingPerformance Group started work in Sep 07 … but dominated by Detector Paper.

4. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 4 Stephen Haywood Relationships Software Hardware Physics Tracking Performance Data Prep Data Quality Align Validation Commissioning Trigger activity working group

5. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 5 Stephen Haywood Detector Paper Detector Hardware & its expected Performance. Eva Bouhova Markus Elsing Daniel Froidevaux Grant Gorfine Stephen Haywood Vato Kartvelishvili Thomas Koffas Jason Lee Michael Leyton Giacinto Piacquadio Troels Petersen Darren Price Christoph Ruwiedel Andi Salzberger Laurent Vacavant Jean-Baptiste de Vivie Seth Zenz Hongbo Zhu

6. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 6 Stephen Haywood p T Resolution  (p T ) =  (  ) (1  p MS /p T ) MS significant up to 40-80 GeV High-p T resolution degraded by lack of TRT C-Wheels Improvement compared to TDR due to  Use of Pixel ToT  Reduced TRT jitter

7. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 7 Stephen Haywood Impact Parameter Resolutions

8. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 8 Stephen Haywood Summary of Resolutions In the Barrel region: 1/p T :  = 0.34×10  3 (1  44/p T ) GeV  1 d 0 :  = 10 (1  14/p T )  m z 0 :  = 90 (1  2.3/p T )  m  :  = 70 (1  39/p T )  rad cot  = 0.7×10  3 (1  5/p T ) GeV  1 So for a 1 TeV muon, p T resolution is 34%.

9. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 9 Stephen Haywood Charge-sign Misidentification Right: p T = 2 TeV Sign identification important for high-p T electrons (muons measured by MuSpect) Electrons suffer from confusion caused by brem and subsequent conversions When resolution very poor (high p T and high |  |), brem reduces p T improving sign identification

10. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 10 Stephen Haywood Reconstruction Efficiency Left: p T = 5 GeVRight: Pions See effect of material Efficiencies O(85)% for medium energy electrons & pions

11. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 11 Stephen Haywood Efficiency in Jets Left:  Efficiency for: Reconstruction, Standard Cuts, b-tagging Cuts  Fake Rate for: Standard Cuts, b-tagging Cuts Right:  Efficiency & Fake Rate for: E T 100 GeV See effect of material See effect of PR confusion in jet core

12. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 12 Stephen Haywood Primary Vertex Resolution With no beam-constraint: t-tbar:  x,y = 18  m  z = 41  m H  :  x,y = 36  m  z = 72  m Reconstruct PV with 100% (96%) eff for t-tbar (H  ) Identify PV at 10 33 cm  2 s  1 with 99% (79%) eff for t-tbar (H  )

13. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 13 Stephen Haywood Secondary Vertex Resolution Left: tau decaysRight: J/  decays Tau decays are more collimated; gives rise to non-Gaussian distributions

14. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 14 Stephen Haywood K 0 s Reconstruction Studied with VKalVrt & V0Fitter (and initially with CTVMFT) Radial resolution sensitive to silicon layers

15. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 15 Stephen Haywood Material Effects Left: ElectronsRight: Photons Geometry: CSC-01 – used for Detector Paper studies CSC-02 – includes improved estimates for services inside Tracking Volumes CSC-03 – includes improved estimates for services outside Tracking Volumes Detector Paper includes X 0 plots made with CSC-03

16. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 16 Stephen Haywood Bremsstrahlung Recovery Left: p T = 25 GeV, End-capsRight: J/  ee Without additional info (eg Calo Cluster), it is difficult to improve measurements – information has been lost ! Investigate how to apply Brem Rec depending on hypothesis (fit, TR) for particle

17. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 17 Stephen Haywood Conversion Recovery Benefit from identification of single-track conversions in TRT To be tested with real events: what is fake rate of conversions?

18. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 18 Stephen Haywood TRT TR Performance Improved determination of TR threshold function from CTB Pion Rejections between 10 and 100 are expected The performance has degraded since the TDR’s

19. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 19 Stephen Haywood First Data Organisation to be understood … at Ringberg Workshop 14-18 Apr. Data Quality = Commissioning Team. Strong connection with Alignment Team. Will discuss and receive input from Beate Heinemann (CDF) at next InDet TrackPerf Meeting on 17 Jan. Where possible, need to establish performance from Data, rather than MC.

20. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 20 Stephen Haywood Efficiencies Min Bias – low p T PR in Jets HLT … for Trigger Community Look at electrons identified in Calo, esp W  e, Z  ee Look at muons identified in MuSpect, esp W , Z  Look at taus in Z  … Oxford work from Maria & Guillaume – see Helen’s talk Conversions: x-check single tracks conversions with reconstructed pairs

21. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 21 Stephen Haywood Resolutions Look at pulls for hit residuals  confirmation of hit errors  nominal track resolutions (bar systematics, such as global distortions) d0 & z0 from PV reconstruction J/  & Z  to confirm p T resolution Strong overlap with Alignment & Calibration, since some of these distributions will be used to determine constants/corrections.

22. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 22 Stephen Haywood Alignment Right: Difference in p T spectra between   and   – sensitive to global distortions (eg sagitta effects) Huge effort, in particular in UK With unaligned detector (build precision), Z  peak is completely washed out

23. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 23 Stephen Haywood Alignment & Calibration Alignment will have significant effect on:  PR in Jets  Vertexing  p T Resolution Alignment – need Level-1 (ECA-B-ECC) alignment asap (Cosmics, beam-gas) B-field – start with measured Solenoidal field Material – start with estimated material; study in collaboration with e/  WG  Brem  Conversions  V 0 ’s – energy loss

24. ATLAS UK Phys @ IPPP – 9 Jan 08 InDet Tracking Performance 24 Stephen Haywood Conclusions Post Detector Paper: CSC Note & Back-up Notes Understand relationships with Commissioning & Alignment Teams Get ready to look at First Data