1. M. Ellis - MICE Collaboration Meeting - Wednesday 27th October 2004 1 Sci-Fi Tracker Performance Software Status –RF background simulation –Beam simulation –Reconstruction –Data sample Expected performance Performance Emittance calculation Summary

2. 2 RF Background Simulation As described by Rikard at VC of 22/9/04 Software used from tag mice-0-9-10 Background generated in 100 jobs of 100 events each on CSF farm at RAL. Total time to produce 10k events on CSF was over 4 days! Output files merged into one file that is then used as input for each of the 10k event samples.

3. 3 TURTLE Beam Added as G4MICE option In CVS as tag mice-0-9-11 720,000 events produced using the “June04” configuration were provided by Kevin Tilley Sample broken up into 72 sets of 10,000 events each for submission as jobs on CSF farm at RAL

4. 4 Reconstruction TDC aspect of Digitisation is now more realistic (exact details of discriminators still to be perfected). Duplets (space point made from 2 views in a station) are now reconstructed and used in the pattern recognition. Individual clusters are used as separate measurements in the Kalman track fit. Still need to add the use of a field map (particularly with the more detailed simulation now in use) – currently assuming a fixed field!

5. 5 Data Sample Four sets of events processed: –Various sets of 20k events to study effects of multiple scattering, non-uniform field, etc... –720k events with all physics processes, but no RF background –720k events with all physics processes and overlaid RF background events –7k events with 100x nominal RF background All performance plots are from the sample with nominal RF and all physics processes. A summary table at the end will show differences between performance with and without RF background

6. 6 Expected Performance Expected momentum resolution based on “back of the envelope” calculations. Determine effect that multiple scattering will have on resolution. Predict resolution as a function of P T and P Z

7. 7 No Multiple Scattering - P T R RR P T = Q B · R  P T = 0.52 MeV/c  P T / P T =  R / R  P T = Q B R  R / R  P T = 1.202 x  R  R = 0.431 mm  R = 0.427 * 3.5 / √12

8. 8 P T Resolution From the previous slide, it is clear that the P T resolution should be flat as a function of P T :  P T = Q B  R So long as the track does not have an excessively high P Z (resulting in the projection in XY being a small fraction of a circle), the P T resolution should also be flat in P Z

9. 9 No Multiple Scattering - P Z  z P Z = P T / tan(  ) tan(  ) = d  / dz 

10. 10 P Z Resolution P Z = P T / tan(  ) The resolution in  depends on the radius of curvature:  tan(  ) = k / P T Therefore the uncertainty on P Z depends on the uncertainty in P T (which is fixed) and that in tan(  ) in quadrature For cases of High P T, or Low P Z, the resolution in P T will dominate over the resolution in tan(  ):  P Z = P Z x  P T / P T High P T (100 MeV/c):  P Z = 0.52 / 100 x 225 = 1.15 MeV/c Low P Z (150 MeV/c):  P Z = 0.52 / 50 x 150 = 1.56 MeV/c  P Z 2 = k 1 2 + (k 2 + k 3 P Z ) 2  P Z 2 = (k 1 / P T ) 2 + k 2 2

11. 11 With Multiple Scattering VXW  ms  z = 1.9 mm X 0 = 42 cm → x/X 0 = 0.45%  ms = √2 x 13.6 MeV /  cp x 0.053 100 < p < 350 MeV/c 68.76 <  cp < 335.1 MeV 3.1 <  ms < 14.9 mrad Not to scale!

12. 12 Point Resolution with MCS 3.1 <  ms < 14.9 mrad Station is 1.9 mm thick Mean total momentum is 240 MeV/c, giving a typical  ms = 5 mrad. MCS produces additional error on the point resolution of between 6 and 30  m. MCS has no appreciable effect on the resolution of measuring an individual point

13. 13 Multiple Scattering - P T Typical distance between planes = 175 mm Error on position = 175 * 5 mrad = 0.875 mm Resolution in R becomes 0.97 mm  P T = 1.202 x  R  P T = 1.16 MeV/c

14. 14 Multiple Scattering - P Z For case of high P T and high P, expect  P Z to depend just on new  P T :  P Z = P Z x  P T / P T = 160 x 1.16 / 100 = 1.86 MeV/c In general, the effects of multiple scattering will increase as P drops, so expect resolution to approach no multiple scattering level at high P and P T, and get worse as the momentum drops.

15. 15 Performance Position resolution –X, Y Momentum pulls –P X, P Y and P Z Momentum resolution –P T, P Z –  P T versus P T,  P T vs P Z –  P Z versus P T,  P Z vs P Z “Primes” resolution –X’, Y’, T’ Efficiency and Purity

16. 16 X Position Resolution RMS = 48.49 mmRMS = 0.391 mm

17. 17 Y Position Resolution RMS = 57.05 mmRMS = 0.392 mm

18. 18 P X P Y and P Z Pulls

19. 19 P T Resolution RMS = 28.65 MeV/cRMS = 1.75 MeV/c

20. 20 P Z Resolution RMS = 25.65 MeV/cRMS = 2.41 MeV/c

21. 21 Resolution vs P T

22. 22 Resolution vs P Z

23. 23 X’ Resolution RMS = 182.1 mradRMS = 8.00 mrad

24. 24 Y’ Resolution RMS = 172.3 mradRMS = 7.91 mrad

25. 25 T’ Resolution RMS = 5.48 x 10 -2 RMS = 5.06 x 10 -3

26. 26 Efficiency vs P T

27. 27 Efficiency vs P Z

28. 28 Efficiency vs P T / P Z

29. 29 Purity vs P T

30. 30 Purity vs P Z

31. 31 Purity vs P T / P Z

32. 32 Emittance Calculation Analysis code developed by Chris: –Trace and phase space –Monte Carlo truth, reconstructed parameters, virtual planes, ICOOL output files... –Can calculate 2D, 4D, 6D emittance, apply cuts, re- weighting, etc... –Performance checked against ecalc9f For each 10,000 event run, calculate one value of emittance from Monte Carlo truth information and one from reconstructed track information. Determine resolution and bias in 4D (XY) emittance (TOF unavailable, hence no 6D emittance).

33. 33 Emittance Resolution

34. RMS of True RMS resolution (no RF) RMS resolution (with RF) RMS resolution (100x RF) % RMS/RMS (no RF) % RMS/RMS (with RF) % RMS/RMS (100x RF) X (mm)48.490.3900.3910.3840.800.810.79 Y (mm)57.050.3910.3920.3890.69 0.68 PT (MeV/c) 28.651.75 1.696.11 5.90 PZ (MeV/c) 25.652.41 2.439.40 9.47 X’ (mrad)182.18.028.008.084.404.394.44 Y’ (mrad)172.37.907.917.584.59 4.40 t’ (x10-3) 5.480.506 0.5199.23 9.47 Efficiency in %Efficiency out %Purity in %Purity out %  4D bias %  4D resolution % No RF99.99(85)99.81(17)99.15(12)99.17(66) -0.1210.060 With RF99.99(85)99.83(43)99.13(14)99.17(57) -0.1380.062 100x RF100.(00)99.(73)95.(28)96.(47) N/A Performance Summary: