Muon Slides 5-December-2001

Bob Handler looked at the difference between outer and inner layers of z-distributions. The time difference between the shadow hit and the real hit is a measure of the location of the real hit in z. Clearly if tracks hit the stack at an angle the outer layer z's will differ from the inner layer z's. Unfortunately our time resolution is not sufficient to distinguish these differences on an event-by-event basis, but it is adequate to look at distributions for particular classes of events. Bob's plots for east and west show the distribution of the outer shadow-real times minus the inner shadow-real times for the interaction bunch (on the right), the non-interaction-related peak with times consistent with a rear hit (the middle), and the non-interaction-related peak with times consistent with hits more forward than the exact rear of the chamber (the left).
Bob used his pair-by-pair time corrections in this analysis. As you can see, the interaction-related peak on the right doesn't show a dramatic shift in time, but the non-interaction peak in the middle shows a significant skewing for west-side tracks. This corresponds to a shift of about 1.1 nsec, or nearly a foot. The difference in radius between the inner and outer is a bit over 3 inches, so the slope of the track is about 4.
Bob used the extreme bins for overflow hits in the left histograms, but not in the others. His TopDrawer Topdrawer file is here.

He used a 2-gaussian fit to the peaks. His results follow:

http://hep.physics.wisc.edu/~jnb/imu/5Dec2001