1. Track Fitting and Comparator Results Emu meeting @ UC Davis Feb. 26, 2005 Yangheng Zheng University of California, Los Angeles  Motivation & Introduction  Results

2. 02/26/2005 Emu meeting @ UC Davis 2Motivations  Check output from comparator chips (for both ME2/2 and ME1/1)  Get familiar with Stan’s track-fitting utility package (TrackFnd)  Test the unpacking software (ORCA/EmuDAQ) for test-beam 2004 data  Look at ME1/1 data from TB2004

3. 02/26/2005 Emu meeting @ UC Davis 3 Stan’s Track Fitting Framework  Pedestal Subtraction  Precision Sampling Time  buckeye shaping  Cross Talk is a function of t s (capacitative+slightly resistive coupling between adjacent strips)  lookup table  Cathode Noise Correlation  unfired events  Fitting Gatti distribution  hit position / each layer  Track Finding  Kalman Filter  Track Fitting  A straight line least squares fit  Details can be found: http://www.physics.ohio- state.edu/~durkin/testbeam03/TrackFnd.htm http://www.physics.ohio- state.edu/~durkin/testbeam03/TrackFnd.htm

4. 02/26/2005 Emu meeting @ UC Davis 4 Data for Gatti Fitting strips time bins Largest pedestal subtracted ADC value INPUT DATA: OUTPUT: track hit position for each layer through the least squares fitting

5. 02/26/2005 Emu meeting @ UC Davis 5 Something New  New interface between TrackFnd and ORCA/EmuDAQ  Add options of gMinuit for fitting distributions of buckeye and Gatti  Change pedestal subtraction method  New constants for ME11  cross talk  cathode noise correlation  Gatti parameters  strip width and no staggering

6. 02/26/2005 Emu meeting @ UC Davis 6 Buckeye Shaping 4*t c

7. 02/26/2005 Emu meeting @ UC Davis 7 Peaking Time t c ME22 (t c  33.25ns) ME11(t c  28ns) ME11: smaller gas gap and wire spacing  shorter drifting time

8. 02/26/2005 Emu meeting @ UC Davis 8 Peak Charge Time Bins ME22 (TB2003)ME22 (TB2004)ME11 (TB2004)

9. 02/26/2005 Emu meeting @ UC Davis 9 Pedestal Subtraction  Standard method: subtracting first two time samples  Method 2: pedestals  empty event (lookup table for every strip)  Method 3: pedestals  fitting all available time samples for every event (buckeye shape + constant pedestal)

10. 02/26/2005 Emu meeting @ UC Davis 10 Pedestal Subtraction (cont.) Method 1 – Method 2Method 3 – Method 2 ME22 (TB2004) Mean 1.041 RMS 3.17 Mean 4.322 RMS 5.901

11. 02/26/2005 Emu meeting @ UC Davis 11 Pedestal Subtraction (cont.) ME22 (TB2004) ---- Method 1 ---- Method 2 ---- Method 3

12. 02/26/2005 Emu meeting @ UC Davis 12 Cross Talk  a function of t s  determined by tracks passed within 0.05 strip width of the center of the strip ME22(TB2003) ME22(TB2004) ME11(TB2004) small statistics t s (ns) cross talk fraction

13. 02/26/2005 Emu meeting @ UC Davis 13 Cathode Noise Correlation  Determined from unfired strips  For time bins i and j,  For time bins 3, 4, 5, 6 (ADC counts)  For ME22, TB2003 and TB2004 show similar results  ME11 shows different noise correlation  No correlations between adjacent strips’ time bins (<1 count) ME22 (TB2003)ME22 (TB2004)ME11 (TB2004)

14. 02/26/2005 Emu meeting @ UC Davis 14 Gatti Parameters  half gas gap (h parameter)  configuration: ME22 4.75mm, ME11 3.00mm  fitting: ME22 4.91mm, ME11 2.99mm  strip width  ME22 8.5-16.0mm, ME11 3.15-7.6mm  number of wire group per layer  ME22 64, ME11 48  strip staggering  ME22 0.5 strip, ME11 no staggering

15. 02/26/2005 Emu meeting @ UC Davis 15  2 of Gatti Fitting NDOF: 9 - 3 - 1 = 5 ME22 (TB2004)ME11 (TB2004) Investigating the large tail effect 0.08 for ME22 = 22 22 Entries Mean 4.99 RMS 3.16 Mean 4.999 RMS 3.16

16. 02/26/2005 Emu meeting @ UC Davis 16 Event Displays ME22 (TB2004)ME11 (TB2004)

17. 02/26/2005 Emu meeting @ UC Davis 17 Residue (3 rd Layer) ME22 (TB2004) ME11 (TB2004 ) sigma=0.0178 sigma=0.0177 3 rd layer removed from track fitting

18. 02/26/2005 Emu meeting @ UC Davis 18 Comparator Ouput Resolution fitted track position - comparator output

19. 02/26/2005 Emu meeting @ UC Davis 19 Left Half Hits vs Right Half Hits wrong output due to the ambiguous charge difference (see next slide)

20. 02/26/2005 Emu meeting @ UC Davis 20 Output Probability wrong assignment due to the ambiguous charge difference

21. 02/26/2005 Emu meeting @ UC Davis 21 Output Efficiency correct comparator output correct strip# output comparator output residue within ¾ strip

22. 02/26/2005 Emu meeting @ UC Davis 22Summary  Unpacking software seems robust  Small changes applied to TrackFnd class  For ME22, results of track fitting of TB2003 can be fully reproduced.  2  For ME11, the large tail effect of  2 and systematic errors are under investigation  Comparator chip produced reasonable results for both ME11 and ME22

23. 02/26/2005 Emu meeting @ UC Davis 23Next  need to understand ME11 data better  more refinements can be done  gain effect  cross talk as a function of chamber position  geometry constants