I analyzed the photon calibration runs and studied the difference in y of the Veto counters and HYCAL.
In these three plots, I am showing the y-difference for runs where the photon beam was incident on a specific y-position of HYCAL. The black curve is a 2 gaussian fit to th e peak and background. In the efficiency calculation, the cut applied was +/-10cm on the y-difference.
Run 5334, y=35cm, x=-25cm
Run 5353, y=-5cm, x=-25cm
Run 5376, y=-35cm, x=-25cm
These plots below show the centriod and sigma from the fits of the y-difference as a function of the y-position of HYCAL.
Efficiency for counter #3 after correcting Veto y reconstruction.
Results after correcting Veto y reconstruction and ADC cuts.
Charged-particle efficiency from pair production run after correcting Veto y reconstruction and ADC cuts where the black(red) points are without(with) y-matching between HYCAL and Veto.
