Hi,
here are the minutes of our meeting yesterday:
Visit of D. Phillips - Post-Discussion
+ Theoretical framework is very nice and highly appreciated
+ CZ received email from D. Phillips, needs to convert file format
+ Extraction of GEn from T20 (Schiavilla and Sick) is not further
improved when T20 is improved, because T20 would only determine the
G_Q piece in A, but the sensitivity to GEn is still coming from A;
and is limited by the uncertainty of A. T20 by itself is
proportional to GC/GQ, i.e. the isoscalar charge form factor, where
GEn contributes at a 5% level only
+ Theory has some flaws though:
Main weakness recognized is the issue to reproduce the quadrupole
moment. In adjusting it, the theory leaves its path from first
principles. Arising uncertainties not quantitatively clear.
+ Discussion about ion polarimeter measurement/theory normalization:
The character of the theoretical uncertainty suggest to push for an
ion pol measurement. A purely experimental error of comparable size
like the theoretical is still preferrable, at least it adds
information.
It's not clear at this point if a measurement is now feasible.
Kinematical corrections: Hydrogen method (EG) vs. MC method (AM)
+ Eugene showing dp=pe-pe(te) vs. pe, for various TOF numbers. Data
from each TOF appear as slices
+ plotting projected dp histograms for individual TOFS: centroids
appear to TOF-number dependent
+ angle reconstruction is fine theta_p - theta_calc(e): centroids
zero, resolution <1 degree.
+ comparing pe and pecalc for different tofs:
- p(theta) much better defined than p
- pe resolution at forward angle (electrons) better than at larger
angle
- proton momentum better defined than electron momentum
+ Momentum corrections for electrons up to 50 MeV
+ Speculations why electron momentum is wrong:
- TOSCA for Cerenkov shieldings?
- Error in magnetic field map or its application
Holding field map (AS, CZ)
+ Not discussed at this time
Inclusive + N-Delta analysis (NM, TF, YX)
+ TF not present, NM has Wednesday class, YX needs more time
Recrunch status and disk space
Recrunch status:
+ Runs 11251-12672 have been lrn'ed with v3.4.4 (i.e. now they have
"proper" DSTs). They are presently in ANALDIR/v3_4_4 and will soon
be moved to $ANALDIR=/net/data/9/Analysis/data.
+ Backup copies of the original online-crunched runs 11251-12672 are
on the buds (md5sum-checked) with links pointing to them in
$ANALDIR/online_crunch.
+ $ANALDIR/v3_4_4 will be used further for lrd-recrunch(es).
+ Runs 12673-13266 have been lrd'ed and are in $ANALDIR/v3_4_4.
+ I will invoke a recrunch with lrn for runs 11250 backwards soon, in
order establish "proper DSTs" and use improved
calibrations. Previous online-crunch results will be temporarily
backed up on the buds with links in ANALDIR/online_crunch.
Disk space:
+ At present, one 750GB spud is completely available, and another,
presently mirrored spud will be available after tape archiving is
complete.
+ Yet another spud (750GB) would be available if pre-production data
are deleted or moved
+ 1.5TB spud10 to be available soon
+ Two mirrored spuds are necessary at all times for DAQ during the new
run
+ Enough space atpresent to start running, but need to extend after
~1 month
+ Desirable to have two analysis partitions, one which covers all lrn
results, and one which covers all lrd results, i.e. two spud raids
for analysis.
+ Consider to spend ~$8k for 2 more (spud11 and spud12), with >2TB
raid servers.
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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