[Sane] Update to plot of 80 deg. asymmetries

[O. A. Rondon]

Hi SANE analysis team,

I have posted an updated version of the plot of the asymmetries for runs
72607 to 72624 taken during the 5.9 GeV 80 deg. period, that I showed at
yesterday's analysis meeting, with run quality labels based on hclog and
run list entries for those runs.

http://twist.phys.virginia.edu/~or/sane/analysis/tot_asym_2.pdf

These runs were originally analyzed by Hovhannes. Runs 614 to 624 were
all taken with the bottom target with positive polarization, as part of
the second half of an anneal cycle. Run 613 was taken to find the cross
hairs and center the target, log  176547
https://hallcweb.jlab.org/hclog/0902_archive/090218071844.html
The beam was centered after run 609. Runs 610 and 611 have SR "Off"
entries in the run sheets, but replay shows the SR was actually on.

The asymmetry plot was made to check if the target polarization is
contributing to the decaying trend in the asymmetry. The plot shows the
counts asymmetry corrected for beam and target polarization, charge per
helicity and dead time (blue open symbols), and without target
polarization (green solid). The sign of the asymmetries has changed
since the plot was first made, due to a correction in the helicity sign
assignments implemented in the analyzer. As a result of this, the charge
and dead time corrections have also changed somewhat, but the trend
persists.

The plot shows that the asymmetries for 614 to 616 were comparable
before the target was shifted vertically. Run 616 was interrupted
for this purpose. No explanation for the ~ 2.5 mm target motion was
logged, only that the motion was done;  (1.704 (before - log 176545 ) -
1.607 (after - log 176561) = 0.1 encoder units ~ 0.1").

Looking at the yields for runs 617 to 624, a less than 15% variation
(with smaller-than-10% errors per run) can be seen in log 176596, to be
compared with a factor of ~3 change in the asymmetry, at the several
sigmas level
https://hallcweb.jlab.org/hclog/0902_archive/090218160227.html
Missing from the plot are the yields for runs 614-616 which may give an
idea of whether the target motion was needed.

So, at least for this set of 11 runs, it looks like run quality and run
yields have little or no connection with the decay of the asymmetry. The
target motion may have contributed, but the yields for the early runs
need to be computed to determine if this is the case.

Someone who used the script to compute the yield on-line should redo it
for these runs, after replaying them with the current analyzer, which
does the correct dead time calculation.

Cheers,

Oscar