[Sane-analysis] Minutes of March 30 Analysis Meeting

[Narbe Kalantarians]

_*James:*_ Switched helicity definitions for charge asymmetry 
calculation (i.e. swapped Hel^+ as Hel^- and vice-versa).  No live-time 
correction applied here. This seems to make the dependence of the 
asymmetries on P_B*P_T disappear. This is an empirical observation and 
requires some more study.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Raw_Asymmetries#Charge_Normalization_Switch:_3.2F30.2F2011


_*Anusha:*_ Summary of slow-raster x and y offsets; SR_x and SR_y, 
respectively. Adding an offset to SR_x seems to have an unexpected 
effect on the out of plane angles. Using these offsets to calibrate the 
beam positions from EPICS; T_x, T_y. Also, checking offsets with 
coincidence data. This procedure seems to fix deltaP, but not really 
deltax, deltay, nor deltaE; delta => measured - calculated. Applying  
SR_x offset alone seems to fix things more than applying both SR_x and 
SR_y offsets together.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Find_srast_x/y_offsets


_*Hoyoung(03/31/11):*_ Seeing discrepancy in data/MC for run 72828. 
Applying tracking efficiency. Will look to see if any other run(s) in 
this group exhibit similar features. Mark is cross-checking this.
http://www.jlab.org/~hykang/pf/20110324/
Some runs seem to give very large packing fractions; ~70%. Oscar 
suggested looking into whether the target length might be more than 3cm 
for these cases, starting by trying this with the MC.
Started looking in to getting radiative corrections. This would be done 
in a way similar to what was done for RSS.


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

Next meeting will be April 6th 3:30pm JLab time

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