Muon Slides 27-February-2002
- Bob Handler has been looking at matching scintillator
times with his stub times. The plot for the
BSU shows the timing of scintillator hits for the scintillators
corresponding to the stub (center) and to each side.
Note the wide differences between east and west. It looks as though
there is a DC level of tracks on the west side. He looks mainly at
the front BSU scintillators, but the rear are only a few nsec later.
- The BMU tracking has been duplicated in the Muon and MuonMods
area, and is currently under test. The imu Fortran files are now gone,
as are most of the scintillator
'hook' routines and the support for e1.exe and e5.exe. When the
BMU stub-finding is verified, the last of the imu and imuMods files
will be removed.
- I used a datafile generated by Ken Bloom because it was handy for
a quick test, with results herein. The phi
distribution looks a smidgeon odd, but is the same in both.
Whether this curious phi distribution is merely statistical or
algorithmic remains to be seen. I suspect statistical. Note that
the distribution is the same between both the new (BMU) and old (IMU)
stub finding. The t0 and chisquared distributions
show some curiosities as well. Note that the t0 is the result of a
3-parameter fit, and is thus only sensible for 4-hit stubs.
The West and East BMU t0 distributions peak on different sides of 0,
suggesting an algorithmic issue in the fitting. The IMU t0 distributions
are both offset, which may reflect a genuine issue with the use of
t0 in simulation and reconstruction. The chi-squared distributions are
quite similar between the old and new reconstructions.
- I ran a simulation of my own, with negative muons in a restricted
phi region and with a specified eta, on the west side. The resulting
t0's and reconstructed Z positions are
displayed here. Something is clearly wrong with the Z
reconstruction. Repeating with postive muons gives the same t0
distribution, and with east muons the reverse. The east muons tend
not to have a reconstructed Z.
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