Attending AS,EG,CZ,YX,VZ,BillT,MK,TA,WX.
-Tavi called, is working on implementing MAID. Contacted vanBuren, has
MAID with built-in radiation by POLRAD. People involved: TF,CZ,YX,AS,NM
-Spin angle map: Comparison for spin angle z-profiles are out.
32 degrees: TOSCA(ZZ) vs. Genya's field map vs. CZ's analysis
47 degrees: TOSCA(ZZ) vs. Genya's field map vs. Karen's field map
Agreement among field simulation, field measurement and analysis is
amazing. Need to evaluate yield-averaged spin angle (only this one
matters for the systematics) for each method. Suggested to consider
difference of average spin angle for measured and simulated field map as
representing the systematic uncertainty on the spin angle. Note that in
Chi's analysis the uncertainty of the spin angle is statistically driven,
and this has been used as the systematic error in the other channels.
Also note that the field mapping can be done much better. I claim that
0.1 degrees are feasible. In this case, the spin angle systematics on GEn
would be down to less than 2%.
VZ
-Systematic error on GEn is 12% per degree. Assuming 0.5degrees = 6% from
CZ's analysis. Second biggest contribution is the systematics of hPz.
-Discussion about hPz: Statistics are <=0.2%; systematics are sensitive to
reconstruction and, perhaps more importantly, to the GEp/GMp form factor
ratio in the region of evaluation. At present, the ratio
hPz(left)/hPz(right) decreases with Q2. This ratio is also sensitive to
GEp/GMp
WX
-GEp/GMp (H2) is down to 0.9+- at Q2~=0.8-0.9(GeV/c)^2 (BATS)
and a slight decrease below 1 in Q2~=0.1-0.6(GeV/c)^2 (TOF)
-GEp/GMp from Deuterium: So far assuming elastic instead of quasielastic.
PWIA/DWIA differ a lot for (e,e'n) but very little for (e,e'p) hPz vs.
Q2 (this is because the quasielastic cross section is a factor 10 larger
for proton knockout than for neutron knockout), so assumption of a free
proton target is justified in the quasielastic limit.
-Recommended to proceed with Aaron's and/or Eugene's momentum corrections.
-Propect of combining hydrogen and deuterium data.
EG
-Set up TOSCA on a windows machine, study effect of Cerenkov shielding
-Works on DST: extracting events. Problem with linking to outer detector,
macro quits out of root at certain event number. lrd seems to succeed
though when processing the same run
-Still sees much more (e,e'n) events passing the same cuts when analyzing
ntuple instead of dst.
-Effect of shielding/converters: Study normalized yields for (e,e'n) and
(e,e'gamma) before and after shielding L15. Even without optimized
timing, quasielastic (e,e'n) sample can be identified by trigger type 2
and quasielastic cuts for electron only. Restrict yield to forward LADS L15.
CZ
-Working on world data parametrization
(refit Abbott = the Chi Parameterization)
TA
-Away nextweek
-Stopped his work on t2d
-Discussion about wire chamber resolution:
DH's method ("neural network") does not provide the resolution of the
Newton fitter. DH's method may replace fast fitter at some point if it
provides better starting momentum for Newton fitter.
Regards,
Michael
--+-------------------------------------+--------------------------+ | Office: | Home: | |-------------------------------------|--------------------------| | Dr. Michael Kohl | Michael Kohl | | Laboratory for Nuclear Science | 5 Ibbetson Street | | MIT-Bates Linear Accelerator Center | Somerville, MA 02143 | | Middleton, MA 01949 | U.S.A. | | U.S.A. | | | - - - - - - - - - - - - | - - - - - - - - -| | Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de | | Work: +1-617-253-9207 | Home: +1-617-629-3147 | | Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 | | http://blast.lns.mit.edu | | +-------------------------------------+--------------------------+
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