[Sane-analysis] Minutes of January 12 Analysis Meeting

[Narbe Kalantarians]

_*Hoyoung(Jan 11):*_ Looked at one of the (5.9GeV parallel) runs that 
have shown significantly different packing fractions with the same 
material load. The 5.9GeV parallel runs had a slow raster radius of 
~1.4cm. Tried increasing the slow raster in the MC to account for this, 
but it only changed the packing fraction by ~1%. Oscar mentioned that 
the MC has too ideal of conditions and a more realistic approach would 
be to place a cut on the data to reduce the slow raster radius to ~0.8cm.
Looked at parallel asymmetries for full sub-set of 
P_HMS=3.2[GeV/c],Theta_HMS=20.2[deg]. Takes charge asymmetry from 
ntuple, which is for every 2s, places cut of delta charge>0.05, and 
integrates to add to the total charge. So a good event passing this cut 
is then incremented, weighting by charge. This turns out to not be too 
different from what is given in the scaler files. The charge is given 
for each helicity pulse and this might introduce some biasing. Will try 
adding the total charge. Also made plot of physics asymmetry A_parallel, 
correcting for polarizations, dead-time, and dilution factor. And will 
provide these plots to James for his talk at the Hall-C meeting.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/HMS_total_asymmetry 



_*Narbe:*_ Worked on absolute comparisons between data and MC for BETA. 
With Mark's help, working on getting cross-section to be in units of 
nb/GeV/sr. Also, cross-section was hard-coded to use atomic and nuclear 
numbers for NH3 only. So this got adjusted to have carbon as well. 
(Slowly, but surely)Reaching some convergence.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/SANE_GEANT#01.2F12.2F2011
Working on getting asymmetries for random backgrounds.


_*James:*_ Updated TE's to include (statistical)errors. Will change to 
standard deviation of points. This will be a part of the overall 
systematics.
https://hallcweb.jlab.org/experiments/sane/wiki/index.ph/Offline_TE_Measurements#Offline_TEs_with_Error:_1.2F12.2F2011
Posted revised copy of his talk for the  Hall C meeting
http://twist.phys.virginia.edu/~jdm2z/sane/hallcwinter2011/HallCWinter2011.pdf


_*Anusha:*_ Looked at plots of ytar, yptar, xptar, and deltaP vs W in 
her MC, for the case of singles. Sees correlations for the ytar, yptar, 
and xptar vs W. Will try also with MC used by Hoyoung and Narbe for the 
packing-fractions.
http://www.jlab.org/~anusha/SANE/targetquan_W1.gif
http://www.jlab.org/~anusha/SANE/targetquan_W2.gif
Posted revised copy of her talk for the Hall C meeting
http://www.jlab.org/~anusha/Talks/HallCUserMeeting2011.pdf
Posted copy of abstract to submit for APS meeting in April
http://www.jlab.org/~anusha/Talks/APS_Abstract.pdf


Whit: Posted a copy of his talk for the Hall C meeting
http://quarks.temple.edu/~whit/SANE/talks/HallC_Users_Meeting_2011.pdf


**A note on the talks: The students will give practice talks this Friday 
(Jan 14th) afternoon 5pm JLab time in room F326/327


_*Oscar:*_ Posted a note on calculating uncertainties for the 
asymmetries on the wiki
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Error_calculation


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

Next meeting will be January 19th at 3:30pm JLab time.
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