1. Run4 Fiducial Match between Real and MC
Purpose
WIS noticed a discrepancy between Real and MC Dch Zed Dch Zed was narrower in MC compared to data
VU extended the discrepancy effects to the study of matches with the outer trackers and also in azimuth
Generally MC looks to have a bigger live area than Run4 data, even when nominal Run4 average dead channel maps are used
If not fixed then the discrepancies will lead to acceptances factors which are too large meaning dN/dy will be too small
Methods
Dipali is making corresponding fiducial cuts between the two dimensional Azimuth vs Zed hits for each outer detector systems
Charlie is looking at the one dimensional distributions between real and MC to spot major discrepancies (plus or minus)
With new fiducial cuts the discrepancies should be minimized
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

2. One dimensional Real and MC distributions
Data
All the valid ++ runs of Run4 stripe 2, 2% of each CNT segment leads to a 1 GByte NTUPLE with track association parameters
Using 40 Phi->KK CNTs simulated generated by Dipali in ++ field
Real and MC histograms are normalized according to total entries
Cuts
Reconstructed momentum from 0.2 to 2.1 GeV/c
Require Dch Quality = 31 or 63
Require Dch Zed to be to cm
Showing only the Dch Zed and Phi (Azimuth) distributions here
Distributions are in the four quadrants for Dch Azimuth comparison, and separated into East and West for the Dch Zed comparison
Future distributions for outer detectors will have 3-sigma matching cuts in Phi and Zed, and will likewise be in quadrants or halves
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

3. Azimuth for Dch SouthWest Best result, practically no significant discrepancies
After normalization by total entries
After normalization by total entries
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

4. Run 4 Fiducial Match for Drift Chamber
Azimuth for Dch NorthWest Almost as good as SouthWest, discrepancy at ~ -19 degrees
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

5. Run 4 Fiducial Match for Drift Chamber
Azimuth for Dch SouthEast Somewhat worse, especially 165o - 168o, 172o - 178o
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

6. Azimuth for Dch NorthEast Unacceptably bad, 1400 - 165o, 175o -200o
There must be a mistake somewhere
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

7. Run 4 Fiducial Match for Drift Chamber
Azimuth for Dch NorthEast Quality = 63 Only No shape change from including Quality = 31 tracks
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

8. Run 4 Fiducial Match for Drift Chamber
Zed for Dch West Looks good except at Z = 0 and at edges Suggest a +/- 70 cm Zed cut instead of +/- 75 cm
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

9. Run 4 Fiducial Match for Drift Chamber
Zed for Dch East, Similar to West except Z=0 discrepancy slightly broader
May 25, 2005
Run 4 Fiducial Match for Drift Chamber

10. Summary of One Dimensional Distributions from Dch
West azimuth looks better than the East azimuth
The North East azimuth comparison is particularly bad Need to confirm that the simulations were done with the latest Run4 Au+Au 200 GeV dead channels map for the Dch
The Dch Zed comparisons are OK except for the Z = 0 discrepancy and a slightly larger extent in real data compared to simulation
More comparisons will be forthcoming for the outer detectors These will largely be influenced by the Dch comparisons
May 25, 2005
Run 4 Fiducial Match for Drift Chamber