Z Vertex



The above left plot shows average z vertex as a function of run index for the L2-G trigger.  The upper plot shows all runs for which the L2-G trigger had production status, while the lower plot shows the first ~100 runs, for which the L2-G trigger had test status.  The above right plot shows a histogram of the points on the above left plot.  These plots show the average z vertex for all the events in a run, that is, they are not limited to pion candidates (as in some of the other QA measures.)




this plot above shows the average z vertex of L2-G events as a function of run index, with outlying runs removed.  To identify outying runs, I took a four-sigma cut around the mean of each histogram (showed top right) and excluded any run for which the average z vertex fell outside this cut.  Currently, I separate the 'test' from 'production' runs for analysis of outlyers.  It would not be hard to combine them if this is deemed preferable.  A list of the excluded runs, with thier average z verex can be found here