1. TB & Simulation results Jose E. Garcia & M. Vos

2. Introduction SCT Week – March 03 Jose E. Garcia TB & Simulation results Simulation results Inner detector SCT system Simulation of Beam Test configuration Setup Results comparison Projects and plans for the future Atlas simulation and reconstruction tools have been used to simulate the TB tracking study with helix fit done last August. 2

3. Software SCT Week – March 03 Jose E. Garcia TB & Simulation results Both DC1 and custom-generated Atlsim data have been used. xKalman++ for the reconstruction. Results are extracted from the combined ntuple (CBNT). Muons of energies from 10 to 500 GeV. More than 20K events for each energy, including runs with high statistics. 3

4. TDR results SCT Week – March 03 Jose E. Garcia TB & Simulation results Left column shows variation with  as in the TDR. Right column results with reconstruction software and data from DC1. In both cases particles simulated are muons with a P T of 20 GeV. Round markers should be comparable (similar field and conditions). Inner TDRInner New 4

5. TDR results (II) SCT Week – March 03 Jose E. Garcia TB & Simulation results All the plots show similar results with a slight deterioration in the forward part. Some changes in software, layout and magnetic field could cause the difference. Inner TDRInner New 5

6. SCT results SCT Week – March 03 Jose E. Garcia TB & Simulation results Simulated stand-alone SCT system 6 Resolution of 1/pT Resolution in 

7. SCT results cont. SCT Week – March 03 Jose E. Garcia TB & Simulation results Simulated stand-alone SCT system 7 Resolution of d o Resolution of cot(  )

8. SCT Results cont. SCT Week – March 03 Jose E. Garcia TB & Simulation results Actual simulation agrees with TDR. It is possible to simulate the behavior of the stand alone SCT. Track parameter resolution with increasing P T becomes flat. Efficiency is around 92% and the fake rate for single muons reconstruction is negligible. 8 P T dependence

9. Setup SCT Week – March 03 Jose E. Garcia TB & Simulation results 9

10. Setup SCT Week – March 03 Jose E. Garcia TB & Simulation results 10

11. Tracking system SCT Week – March 03 Jose E. Garcia TB & Simulation results To compare simulation and TB results 20K muons with P T = 500 GeV,   0 have been used. This situation is similar to the TB due to the small curvature at this energies ( xKalman++ is not able to disconnect the reconstruction from magnetic field). Parameters of the helix fit from TB ATLAS. An example of distributions is shown below, TB results in red and simulation in white. TB 11

12. Tracking comparison SCT Week – March 03 Jose E. Garcia TB & Simulation results Looking closer peaks due to the binary readout can be seen in testbeam and simulation. Adding the pixels to the simulation the “peaks disappear”. Pixels + SCT Test Beam SCT 12

13. Tracking comparison (II) SCT Week – March 03 Jose E. Garcia TB & Simulation results Resolutions for TB and simulation of the SCT are similar. Slight deterioration for 1fC with respect to 1.2fC. Precision Tracker resolution are given for comparison. 13

14. Conclusions SCT Week – March 03 Jose E. Garcia TB & Simulation results Beam test tracking is compatible with full simulation + reconstruction. The same study with magnetic field is needed. Different energies (P T ) should be used. The dependence of the wrong sign fraction could be checked with the 100 GeV beam. For track parameters lower energies are needed. Effect of multiple scattering can be analyzed adding more material (cooling pipe,…) in the TB setup. The same tools could be used with new data. 14