[G8b_run] Polarization study part 2

[Michael Dugger]

Hi,

I have spent some time going through my code that is related to the 
modification of the polarization values, and have created some new plots. 
In particular, I have new comparison plots that show ratios and 
differences of the modified polarization to the unmodified polarization. I 
have also made some plots that serve as a sanity checks. All of these 
plots are included in a new presentation.

Note:
I have verified that the code I sent out on November 9th should modify 
the polarization the same way that the polarization is modified in my 
code.

During one of the g8b meetings, I made the comment that the 
modification of the polarization were probably only a few percent. I came 
to this conclusion by looking only at one edge setting and polarization 
plane (1.9 GeV PARA). After looking more closely into the polarization 
ratios, I discovered that the 1.9 GeV PARA set was not a fair 
representation of the entire data set. I was wrong about the general size 
of the modifications. I think it is accurate to state that the 
modifications to the polarization are typically less than 10% but can be 
larger.

Because no one else has the statistics that the pi0 channel affords me, it 
is easiest for others to compare the changes in the polarization to my 
plots, to check that the modification code yields similar results to mine.

Of course, it would be best if someone could verify that the 
consistency of the overlap regions conform to what I see, but I realize 
it is difficult to obtain precise results for reaction signatures other 
than the single pion reactions.

The new presentation can be found at:
http://wwwold.jlab.org/Hall-B/secure/g8b/ASU/polCorrectionV2.pdf

In case you don't want to look at all the slides. Here are a few slides 
that may be of interest:

On slide 2 I state the cuts needed to obtain the results presented.

On slide 3 I have a table showing the self consistency of the data when 
corrections are applied, and when corrections are not applied.

On slide 8 there is a disclaimer regarding the 2.1 GeV data set.

Slides 9-14 show comparisons of the modified polarization to the original 
polarization. These are the plots that should be used to check if your 
polarization-modification code gives the same results as I have.

Take care,
Michael