[Sane-analysis] Minutes from 12/02/09 Meeting

[Narbe Kalantarians]

*_Narbe_*:
Working on altering HMS(single) MC for BETA. With help from Mark Jones, 
got a simple version where "BETA" is a box with the actual dimensions. 
This is to set up for obtaining dilution factors for the BETA data. Will 
work on making it more realistic later on.


*_Hoyoung_*:
http://www.jlab.org/~hykang/HMS_asym/?M=D
Redid HMS and BETA asymmetries with Hovannes' updated code. The signs 
for these now seem consistent. The different shapes can be attributed to 
the different kinematics for each spectrometer.

Also made a table of  the asymmetries (HMS right now). The dead-times 
used are those for BETA though. Will redo and also make one for BETA.

_*Anusha*_:
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Tracking_Efficiency
Working on tracking efficiency for coincidence data. Efficiency for the 
coincidence data has been low (approx 40%). The polygon cut managed to 
recover only about 2%. Looked at Cerenkov time spectrum, where 
coincidence timing is shifted to about 5ns and reshifted that to 0 to 
make timing cuts more feasible. This only gained about 0.5%. Looked then 
at hdc 1 and 2 and found there is a considerable amount of background. 
And selecting the coincidence from the rest of the data (via tracking).

_*
Luwani*_:
http://www.jlab.org/~lzwano/BMP_71809-71914.pdf
Looked at early runs (around 01/24/09). These were around the times test 
runs , cross-hair, and beam position studies were being done. Will look 
at first C and NH3 runs that started around 01/30/09. This is 4.7GeV 
perp data.
Made color SR plots and will show next time. Working on finals during 
right now so can only devote so much time.

_*
James*_:
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Magnet_Re-energization_Log
Made a log of the times the target magnet was reenergized during 
running. This also lists when heater was turned on.
Obtained EPICS data relevant to target from database Steve Wood prepared 
into a spreadsheet on TWIST. Will use this to look at microwave 
frequencies and online target polarization during for the runs that have 
been showing asymmetries decaying to zero, seen in previous meetings.


_*Jonathon*_:
Looking at asymmetries with SR region cut. Has not seen any dependence 
of asymmetries on SR for the parallel field data. Oscar has seen such 
dependence in the perpendicular data. Will look more into this.

Pertaining to the issue of the decaying asymmetries, there was 
discussion of whether this could be from beam.
There is a summary of the Moller information 
https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Moller_Polarimeter
There doesn't seem to be enough difference seen to account for the 
amount of decay. It could also be useful to check the other halls to see 
if they noticed any significant polarization decay during that time.
Oscar suggested looking at HMS asymmetry as a function of the beam z 
vertex, to see if this changes over the z-vertex. The potentially useful 
data for doing this is HMS data at theta=22degrees.


_*Whit*_:
http://quarks.temple.edu/~whit/SANE/ANN/
Looking at neural-network for both BigCal as well as magnetic field for 
target studies. Mapped reals (E,theta,phi) comparing simulation and 
neural-network results (nn_bcplane_***.ps).

Made plots (BC_***.ps) of BigCal blocks (top) and positions (bottom) 
populated in parallel and perpendicular field settings (field_***.ps). 
Found discernible differences from the 2 settings.
 





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