[Sane-analysis] Minutes of Dec 1st Analysis Meeting

[Narbe Kalantarians]

_*James:*_ Made a table giving half-wave plate status for each run.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Half_Wave_Plate_Notes
Found what was causing unexplained sign change in asymmetry for some of 
the runs. The HWP status was not written in for these specific runs. 
This corrects the sign of the asymmetries for these runs. Also, 
redefined asymmetry calculation changing sign of the asymmetries, making 
them consistent with world A_1 data.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Raw_Asymmetries#Asymmetry_Sign_Flip_Fixed.2C_Overall_Sign_Change_Made:_12.2F1.2F2010
Will revisit tracking study this coming week.


_*Hovhannes:*_ Looking at Cerenkov efficiency. Comparing data to 
(GEANT)MC. Applies some normalization to obtain the relative 
efficiencies. They don't appear to be uniform. The lower region of 
BigCal and corresponding to the larger polar angle theta appears to have 
low efficiency. One possibility Hovhannes suggested is one of the 
Cerenkov mirrors might have been misaligned. 2 of the bottom mirrors 
weren't working too well during the running. The really high 
efficiencies in the upper parts around the edges are from over-correcting.
Looked at asymmetries in slices (~2degrees) of azimuthal angle phi. 
Applying efficiency correction seems to make asymmetries get more consistent
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Cerenkov_efficiency_and_angle_dependent_asymmetry
Will look at theta distributions in bands of theta (~5-10 degrees).  
Whit will take look at this as well with his GEANT4 MC.


_*Jon:*_ Redid BigCal energy resolution study using looser cuts from 1st 
attempt, which was cutting out too many events. Now sees a more 
symmetric pi0 mass peak. Gets

sigma_E' = 0.2021/sqrt(E') - 0.06944

https://hallcweb.jlab.org/experiments/sane/wiki/index.php/JrmEResolution
Will loosen cuts some more to get flatter background, to combine with 
Gaussian for fitting.


_*Anusha:*_ Comparing dat/MC for NH3 run to study nitrogen-14 
contribution. Using NH3 run 72790 and scaling with carbon run 72782, 
obtains same packing fraction of ~47.9% as what Hoyoung had calculated. 
It should be noted that this MC is different from what is used for 
getting the packing fractions and this is also a different analysis. 
This is one of the runs from a specific load that produce a small 
packing fraction in the perpendicular data taking and a larger packing 
fraction in the parallel data taking after it.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/MC_with_NH3
Will look at slow raster distributions and compare data/MC to see if 
there is some evidence of beam being in a different spot.
Wrote an abstract to submit for William&Mary graduate research 
symposium, due this Friday Dec 3rd.
http://www.jlab.org/~anusha/Talks/WMAbstract.pdf


_*Narbe:*_ Prepared spreadsheet that generates (kinematic) binning table 
for BETA. This operates on the energy resolution obtained by Jon and 
generates bins via recursion relation. inputting beam energy and Q^2 
value, generates tables in the format

Q^2  E_Beam  E'  Theta  x   W

The E', x, and W have also their upper and lower edges written out.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Kinematics
Will check to see if widths are reasonable and then talk with Eric 
Christy to start getting radiative corrections, as well as Frank 
Wesselmann for getting the polarized radiative corrections.


_*Hoyoung:*_ (Dec 2) Redid HMS asymmetries for perp runs (72824-72831) 
using beam polarization table prepared by James. Looked at W dependence 
of these asymmetries. One of the runs (72826) has an opposite sign for 
its asymmetry. Flipped its sign to make it agree with the other runs. 
Other than that, asymmetries seem reasonable. Also applied dilution 
factor. Looked at asymmetries for parallel runs (73013-73018). These 
seem fairly consistent. Similarly, applied dilution factor and look at W 
dependence. Significantly increased MC statistics for  getting dilution 
factors.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/HMS_total_asymmetry
Will work with Mark to implement live time corrections. After covering W 
ranges, will work on radiative corrections using similar method used by 
Karl for RSS. Will also look at slow raster distributions comparing 
data/MC as well as beam positions to cross-check with Anusha.


As always, please let me know if I missed anything or if I made any 
mistake(s).

Next meeting will be Dec 8th at 15:30.


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