Hi,
please find the minutes of the analysis meeting below and in the meeting
directory
http://blast.lns.mit.edu/PRIVATE_RESULTS/USEFUL/ANALYSIS_MEETINGS/meeting_070201/
The next analysis meeting should be in about four weeks. Since Thursday
9am doesn't work out well for various people, I'm suggesting Tuesday or
Wednesday. However, excluded are
Tue 2/27 12:00 Lunchtime seminar
Wed 2/28 16:00 Special seminar
My suggestion:
1) Tuesday 2/27 9am
2) Wednesday 2/28 10am
Let me know your preference. I'm voting for 2).
We want to try to keep the chosen time for future analysis meetings.
We will have the next BLAST collaboration meeting on Friday 3/30, with a
special focus on the presentations scheduled for the APS meeting in
Jacksonville 4/14-17.
Ulf Meissner will visit MIT on March 9.
Best regards,
Michael
Minutes of the Blast analysis meeting on 2/1/2007:
-d(e,e') for GMn
+welcoming MIT junior student Adele Schwab. Adele will work on the
analysis of GMn from d(e,e')-inclusive.
-d(e,e'n)
+Eugene presenting (see ppt file)
+investigated alternative methods to extract GEn.
a) By correcting each raw asymmetry A(Q2,thetastar) with the MC ratio
PWIA/FSI and then fitting for A_perp and A_par where A_perp is
directly related to GEn/GMn
b) By first fitting raw asymmetries A(Q2,thetastar) for A_perp and A_par
and then correcting each coefficient with MC ratios PWIA/FSI
separately -d(e,e'p)
c) By correction measured asymmetries with MC difference (PWIA-FSI)
additively rather than multiplicatively
+results are in the ballpark, however can become unstable when divisions
by small numbers occur
+the "full" (previous) way of extracting GEn by comparing measured
asymmetries with MC for various input values of GEn differs significant
between thetacms and pmiss as dependent variables. Reason is
disagreement of MC yields versus thetacms, which is better for pmiss.
Disagreement in thetacms dependence is likely due to inadequate
resolution in MC (0.3 degrees instead of ~1.5 degrees suggested by the
width of the LADS bars.
+Results otherwise close to final.
-d(e,e'p)
+Adam presenting on cuts and kinematic corrections (see two ppt's)
+studied effect of Cerenkov cut(s), and "beta" cut
+carried out various methods of kinematic corrections for quasielastic
disintegration, after preselecting clean d(e,e'p)n data sample which is
overdetermined by one dof:
a) All deviation in Mmiss attributed to offset in pe', while leaving all
other variables unchanged. This shifts the electron momentum by ~14
MeV in average, carried out event-by-event.
b) The Mmiss offset is shared by offsets in electron and proton momenta,
by doing a Taylor expansion and requiring identical relative offsets
for proton and electron momenta, event-by-event.
c),d) Same as a),b), but with parametrized correction instead of
event-by-event correction.
+Aki working on coherent pion production d(e,e'd)pi0 and radiative
effects.
+Yuan working on maximum likelihood extraction of response functions,
problem how to treat empty-target background in this method
+-------------------------------------+--------------------------+
| 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. | |
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| 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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