[SBS_sim] update on timing cuts

[Kalyan Allada]

Hi all,

Here is an update on timing cuts in the tracking analysis. I used the 
first three samples on each strip, as was suggested.

1. The timing cut here does not refer to the fit method that Vahe did a 
while ago. Fitting samples for each strip slows down the analysis by 
order of magnitude, so it is impractical. Here I define timing cuts as 
simple conditions that I apply to remove off-timed signals. It 
essentially does the same thing. For example signals like (fig1. and 
fig2) can be eliminated with this method. Fig 3 is a good signal.

2. The tracking efficiency is shown in trk_eff_new.gif file. The 
improvement for the full background run is decent, although we still 
need to work on the absolute efficiency numbers. I guess the next thing 
we can do is to work on clusters.

3. To show that point #1 is correct, I plotted time (using Vahe's fit) 
for full background run with and without my simple cuts. You can see 
that the peak narrows down considerably( see time.gif).

Kalyan



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