User name X. Zheng
Log entry time 15:18:00 on July10,2001
Entry number 65750
This entry is a followup to: 65641
keyword=Helicity check using cosmic eventsFigure 1 is a plot of "cosmic asymmetry" from 295 (left arm) and 287 (right arm)
data taking runs. Here "cosmic events" are defined as zero track events.
"Cosmic asymmetry" is helicity related asymmetry, not corrected for charge
asymmetry - same as Alexandre's definition (Entry #65641).
Cosmic (zero track) symmetry for left arm is 0.001096 +/- 0.000286
right arm is 0.000404 +/- 0.000308
Figure 2 is a plot of "cosmic asymmetry" from 259 (left arm) and 183 (right arm)
data taking runs. "Cosmic events" are defined by cutting on the second timing
peak in S1 tdc_c. "Cosmic asymmetry" is defined the same way as Figure 1.
Cosmic (second timing peak) asymmetry for left arm is 0.001073 +/- 0.000348
right arm is 0.000367 +/- 0.000461
The following descriptions are the same for Figure 1 and 2:
T4 (or T2) events have been used, after helicity related livetime correction.
The error bar here is 1/sqrt(N3) (or 1/sqrt(N1)), where N3 (N1) is the number of
event T3 (or T1).
For each run, T3:T4 is about 10:9 (for zero track cosmic events, Figure 1);
and 3:2 (for second timing peak cosmic events, Figure 2)
top left: left arm asymmetry vs. number of runs
top right: right arm asymmetry vs. number of runs
middle left: livetime correction factor for helicity + (red) and - (green), left arm
middle right: livetime correction factor of helicity + (green) and - (red), right arm
bottom left: charge asymmetry vs. number of runs (not used here), red markers
...................are for left arm and blue ones are for right arm.
bottom right: results
FIGURE 1
FIGURE 2
