Slides 22-January-2003

• There is a hole in the center of a t0 vs t2 distribution, about 25 nsec wide, almost certainly due to the cross-talk suppression. Bob says we still get some cross-talk, but I need to revisit this and see how deep the cut needs to be.
• There is a curious structure in the t0-t2 vs width2 and vs width0 distributions. Never mind the deficit near t0-t2 (raw time in cell 0 minus raw time in cell 2 for good CdfMuons), which we don't understand either. Look at the extra lines at +-45 degrees. They correspond to things like t0=t2+width2: rise time in cell 0 matches the fall time in cell 2!? Why should this be so common?

  Bob says it is a variety of crosstalk where the positive-going strong pulse induces a signal which tends to terminate the hit in the other wire.

  Speaking of crosstalk, I plot the square root of the sum of the deviations of the times from the average versus the square root of the sum of the deviations of the widths from the average for all 3-hit combinations, and find these plot. That on the left is from raw data from run 151812, and that on the right from a dst made from trigger runs 5 and 6. Clearly a cut of 10 nsec on this time average and 16 nsec on the width is adequate for the job. When I plot the maximum deviation given the above cuts on the square root of the squares, I find that a cut of 13 nsec on the time deviation and 20 on the width deviation does about the same thing: The first cuts 735 entries and the second cuts 695 entries. So I'll modify BMU_DtoE.cc accordingly.

Modified 24-Jan-2003 at 12:29

http://hep.physics.wisc.edu/~jnb/imu/22Jan2003

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