Hi Michael,
I have spent a couple of days trying to update my analysis, mostly looking
into the spin angle issue (I am using crunch v3_4_18).
Here is the procedure I have used (I am not sure if I used Doug's macro
the way I was supposed to, please correct me if I am wrong):
1) from the left and right asymmetries, using the first Q^2 bin and the
Hoehler parametrization, I determined hPz and the spin angle by plotting
the two straight lines obtained by varying the spin angle and looking for
the intersection of the lines:
http://einstein.unh.edu/~adrian/spinAngle/dilutionVsSpinAngleV3_4_18.gif
I obtained hPz = 52.5% and spinAngle = 48.3 deg as it can be seen in the
figure. The error bars for hPz in the above plot were pretty much
determined by the experimental asymmetry errors - if hPz = a/A, with "a"
being the experimental asymmetry and "A" being the theoretical undiluted
asymmetry, then one propagates the errors etc. - the error in "A" comes
from the uncertainty in Q^2 which I considered small for this purpose
(0.001); I still need to determine what this uncertainty really is based
on the electron-proton discrepancy (it used to be quite large before the
wire chambers were recalibrated).
Please note I only used the first Q^2 bin for this polarimetry purpose...
2) Using Doug's macro, I take the Q^2 bin by Q^2 bin profile of
theta(z)-theta(intersection), where theta(intersection) is the angle
obtained from the above intersection of the two sector lines (48.3).
Here are the numbers I obtained:
###################################################################
Bin: 1
Left Spin Angle Profile: -1.01032
Right Spin Angle Profile: -1.0286
###################################################################
Bin: 2
Left Spin Angle Profile: -1.12937
Right Spin Angle Profile: -1.00598
###################################################################
Bin: 3
Left Spin Angle Profile: -1.00653
Right Spin Angle Profile: -0.922306
###################################################################
Bin: 4
Left Spin Angle Profile: -0.729126
Right Spin Angle Profile: -0.972705
###################################################################
Bin: 5
Left Spin Angle Profile: -0.955302
Right Spin Angle Profile: -0.963492
###################################################################
Bin: 6
Left Spin Angle Profile: -0.949572
Right Spin Angle Profile: -0.779735
###################################################################
Bin: 7
Left Spin Angle Profile: -0.890052
Right Spin Angle Profile: -0.932958
###################################################################
Bin: 8
Left Spin Angle Profile: -1.01228
Right Spin Angle Profile: -1.0968
###################################################################
I am not sure I used Doug's macro the way it was intended, please let me
know if I misunderstood.
Anyway, using the spin angle determined above (48.3 deg) I obtained the
following plot for the form factor ratio:
http://einstein.unh.edu/~adrian/spinAngle/geGm_V3_4_18.gif
Please note the perfect agreement with Hoehler of the first data point (of
course since I trusted it completely to determine hPz and the spin
angle)...
Like I said at the beginning of my email, this is very preliminary. My
wire chamber cuts looked OK but I would need to spend more time
doublechecking. However I wanted to send this out before the meeting on
Wednesday.
Thank you,
Adrian
------------------------------------------------------------------------
Dr. Adrian Sindile Room 205A, DeMeritt Hall
Research Scientist phone: (603)862-1217
Xenon Imaging Center & FAX: (603)862-2998
Nuclear Physics Group email: asindile@unh.edu
University of New Hampshire http://einstein.unh.edu/~adrian/
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