[Sane-analysis] Minutes of November 17 Analysis Meeting

[Narbe Kalantarians]

_*John:*_ Looking at efficiency plots for Lucite bars. Plotted 
efficiency versus position. Efficiency is defined:

Hit in lucite (both left and right side) + Cerenkov + Tracker+BigCal / 
Hit in Cerenkov + Tracker+BigCal

For parallel run (72490) sees about 50% efficiency and about 25% for 
perp run (72957). Will check for cut on cluster energy and also look at 
timing (TDC). Results seems fairly reasonable.
https://hallcweb.jlab.org/experiments/sane/german/72490/smallbin/eff_bars_1_thru_9_72490.eps
https://hallcweb.jlab.org/experiments/sane/german/72490/smallbin/eff_bars_10_thru_18_72490.eps
https://hallcweb.jlab.org/experiments/sane/german/72490/smallbin/eff_bars_19_thru_27_72490.eps
https://hallcweb.jlab.org/experiments/sane/german/72957/smallbin/eff_bars_1_thru_9_72957.eps
https://hallcweb.jlab.org/experiments/sane/german/72957/smallbin/eff_bars_10_thru_18_72957.eps
https://hallcweb.jlab.org/experiments/sane/german/72957/smallbin/eff_bars_19_thru_27_72957.eps


_*James:*_ Looked further in to mysterious change in sign of measured 
double-spin asymmetries noticed for 3 particular runs (72945-72947). It 
was assumed that 3 runs may have had their hwp status inexplicably 
changed during data taking on March 8 2009. This was seen in the EPICS, 
but Hall A was also taking data at this time and didn't see that. Now 
thinking it could be due to an IOC reboot that occurred around that time 
as well.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Raw_Asymmetries#Half_Wave_Plate_Status_Follow-up:_11.2F17.2F2010
Working some more on tracking to Front Tracker. Fixed a bug in his code 
where he was applying a fitting factor of 0.3 one too many times. The 
tracking seemed to be bending opposite of its actual direction. This was 
due to a sign convention that needed to be applied.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Particle_Tracking_to_Front_Tracker%2C_Target#Tight_Cuts:_Phi_Bdl_lab_vs_Phi_e:_11.2F17.2F2010


_*Anusha:*_ Comparing data and MC for a Carbon run (72870). Correcting 
optics in MC with a 1st order SR correction. Getting better agreement 
between data and MC. Though xptarg is still some off. Will try using SR 
correction used in SIMC. Will also look at plotting W vs. xptarg. Oscar 
suggested that Hoyoung and/or Narbe look at this Carbon run as well with 
the MC they use for getting packing fractions.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/MC_with_NH3  
**(Bottom, lower right side plot)


_*Narbe:*_ Looked at physics angle and position distributions with 
current SANE-GEANT. Looked at parallel, perp, and no field settings. 
Compared throwing electrons and positrons for the physics angles. This 
was done partly because Jon was comparing the current version of the 
SANE-GEANT with the original version and was seeing a difference in 
distributions in regard to the gain volume, which is based on the 
surface area of BigCal. One key difference to note is that both the 
generated and reconstructed parts in the current version rely on there 
being a cluster event. Also, the peculiar structures seen in the 
reconstructed physics angle distributions may be from a flag requiring 
the Cerenkov fire before reconstructing, possibly photonic.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/SANE_GEANT#11.2F17.2F2010
Also working on the kinematics binning.


_*Luwani:*_ Looking at pi0 decay. Working on calculating pi0 energy from 
the determined pi0 mass to compare with electron energy for background.
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Background_from_Pi0_decay


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

Next meeting will be December 2 ate 3:30pm, after Turkey Day.
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