Checks of TOF Fiducial Cuts Charles Maguire Group Meeting, Nov 28

Checking Goals (TOF only here) Quantify the effect of the fiducial cuts Check all the momentum bins (showing only 0.325 MeV/c here) Look at both real data and simulation Fiducial cuts are introduced at least partially to improve the correspondence between real and simulation distributions Yield analysis should be stable if there are small changes in the fiducial cuts -- not yet confirmed by our group Current findings (using lowest momentum bin data) First quarter of ++ field runs has significant dead area (174o-178o) which was fixed in the later ++ runs and the start of the -- field runs This dead area re-appeared in second quarter of -- field runs Also a new z-localized hole in South side fourth quarter -- field runs These dead areas are not addressed so far in simulation Also determined excess fiducial cutting at lowest azimuth (< 1620) November 28, 2005 TOF Fiducial Cut Check

Z vs Phi for ++ Field First and Second Quarters (0 Z vs Phi for ++ Field First and Second Quarters (0.3 to 2 GeV/c) Dead area 174o-178o in First Quarter (not in cuts) First Quarter of ++ Field Runs Second Quarter of ++ Field Runs November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c (++ Field) Real Data, first quarter ++ Simulation South Positive North Positive South Positive North Positive South Negative North Negative South Negative North Negative Unnecessary cutting of positive particles below 1620 (both North and South) Region 172o-178o is badly reproduced in the simulation for positive particles November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c (++ Field) Real Data, second quarter ++ Simulation South Positive North Positive North Positive South Positive South Negative North Negative South Negative North Negative Still unnecessary cutting of positive particles below 1620 (both North and South) Region 172o-178o is better reproduced in the simulation for positive particles November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c First Half ++ Field Sim (red line) vs Real (black points) Before Cuts Sim (red line) vs Real (black points) After Cuts South Positive North Positive South Positive North Positive South Negative North Negative South Negative North Negative Positive particle shape is not much improved using fiducial cuts Negative particle shapes were acceptable before cuts, little change after November 28, 2005 TOF Fiducial Cut Check

Third Quarter of ++ Field Runs Z vs Phi for ++ Field Third and Fourth Quarters No major differences in second half of ++ field runs Third Quarter of ++ Field Runs Fourth Quarter of ++ Field Runs November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c Second Half ++ Field Real Data, second half ++ Simulation South Positive North Positive South Positive North Positive South Negative North Negative South Negative North Negative Positive particle shape is not much improved using fiducial cuts Negative particle shapes were acceptable before cuts, little change after November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c Second Half ++ Field Sim (red line) vs Real (black points) Before Cuts Sim (red line) vs Real (black points) After Cuts North Positive South Positive South Positive North Positive South Negative North Negative South Negative North Negative Mostly good except for missing positive yield on North side 172o-176o November 28, 2005 TOF Fiducial Cut Check

Re-appearance of 172o-178o problems Z vs Phi for -- Field First and Second Quarters (0.3 to 2 GeV/c) Some differences between first and second quarters of -- field runs First Quarter of -- Field Runs Second Quarter of -- Field Runs Re-appearance of 172o-178o problems November 28, 2005 TOF Fiducial Cut Check

Z vs Phi for -- Field Third and Fourth Quarters (0 Z vs Phi for -- Field Third and Fourth Quarters (0.3 to 2 GeV/c) No major differences between third and fourth quarters of -- field runs Third Quarter of -- Field Runs Fourth Quarter of -- Field Runs November 28, 2005 TOF Fiducial Cut Check New small hole at z = -20 cm

TOF Fiducial Cut on 325 +/- 25 MeV/c First Half -- Field Real Data, first half -- Simulation South Positive North Positive South Positive North Positive North Negative South Negative North Negative South Negative Similar unncessary cutting below 162o in negative particles, North and South November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c Second Half -- Field Real Data, second half -- Simulation South Positive North Positive South Positive North Positive North Negative South Negative North Negative South Negative November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c First Half -- Field Sim (red line) vs Real (black points) Before Cuts Sim (red line) vs Real (black points) After Cuts South Positive North Positive South Positive North Positive South Negative North Negative South Negative North Negative Positive particle shape are reasonably well reproduced Negative particle shapes have the problem in the 174o-178o region November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 325 +/- 25 MeV/c Second Half -- Field Sim (red line) vs Real (black points) Before Cuts Sim (red line) vs Real (black points) After Cuts North Positive South Positive South Positive North Positive South Negative North Negative North Negative South Negative November 28, 2005 TOF Fiducial Cut Check

Explanation and Summary Slide 9 Explanation Left side is for real data and right side is for simulation: 325 +/- 25 MeV/c Real data are for all good quality tracks into TOF, first half of ++ field runs Simulation data used pions, same temperature spectrum as in real data Black line histogram is before cuts, red histogram (mostly on top of black) is for the after cuts using fiducial cut file from Dipali and Debsankar Black filled histogram is for the particles eliminated by the cuts Slide 9 Conclusion Unnecessary cutting of positive particle yield below 162 (see also slide 2) Same input as slide 1 but simulation and real results are overlaid Normalization is based on the total entries ratio (only shapes are relevant) Left side is before the fiducial cuts, right side is after the fiducial cuts Slide 9 Conclusions Also shows unnecessary cutting for positive particles below 1620 Negative particle shapes are in generally good agreement (only one big hole) Positive particle shapes above 1800 reasonably agreement between MC and Real Positive particle shapes below 1800 not as well reproduced, especially South side November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 975 +/- 25 MeV/c (++ Field) Simulation Real Data South Positive North Positive South Positive North Positive South Negative North Negative South Negative North Negative November 28, 2005 TOF Fiducial Cut Check

TOF Fiducial Cut on 975 +/- 25 MeV/c (++ Field) Sim (red line) vs Real (black points) Before Cuts Sim (red line) vs Real (black points) After Cuts South Positive North Positive South Positive North Positive North Negative North Negative South Negative South Negative November 28, 2005 TOF Fiducial Cut Check