History: Luminosity Dependence

+ -=BB tracking yield with Luminosity=-
+ Also looked at the BB tracking yield per Coulomb for T2 triggers. The image below shows the number of tracks found in BB with B.tr.p[0]>0 for T2 triggers. The track yield is normalized by the density of protons in the target, the accumulated charge, and corrected for the T2 DAQ livetime. The red points are from the hydrogen runs at different currents, and green from the nitrogen runs at different pressure.
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+ {img src=show_image.php?id=60 }
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+ Four of the points show a stable tracking efficiency as the luminosity changed. However the highest current Hydrogen run 4596 shows a ~15% drop compared to the other hydrogen runs, due to the MWDC's dropping out during the middle of the run. Correcting the accumulated charge, neglecting this period, leads to T2-tracks/Coloumb that is independent of luminosity.