Slides 2-October-2002

I am trying to get a handle on fiducial cuts for the scintillators and see how these can be used for quality cuts. The rather dramatic change in the number of 3-hit stubs found demands that I spend time on this...
For the IMU trigger run number 4, requiring that a TSU counter be associated with a BMU stub in phi (no other requirements), I get an abs(Z) distribution as shown here. When I add a chi-squared cut and demand that the time of the TSU hit not differ from that of the t0 of the stub (subject to an offset of 62.92 nsec), the result tightens the Z distribution somewhat. Not as much as I'd like, but some.
For the same sample, using the BSU, I ask for the difference between the center of the BSU Z (there are two, forward and rear, with centers 160 cm apart) and the Z found for the stub. The distributions look rather similar, which is good, since they are relative to different BSU Z's. The spikes are due to pileups in Z at the chamber ends. Some chambers are shifted in Z relative to others, so the trailoff is not sharp.
Note that all studies given here which use a t0 of the stub use Bob's algorithm. I tried transplanting the t0-finding code into the old algorithm, but the results are not clean. I found my bug, and the results now look much better.

Modified 9-Oct-2002 at 11:17

http://hep.physics.wisc.edu/~jnb/imu/2Oct2002