Agenda:
-Radiative effects in the MC generator - Mascarad (VZ,NM,..)
-Discussion on how to extend to ed elastic scattering (PK, CZ), and
e,e'N quasielastic scattering (VZ)
-Update on GM from T11e in ed vector-polarized elastic scattering (PK)
-Agenda for Wednesday August 24, 2005
Find these minutes along with VZ's and PK's talks on
http://blast.lns.mit.edu/PRIVATE_RESULTS/USEFUL/\
ANALYSIS_MEETINGS/meeting_050817/
Attending KD,JC,TA,RF,NM,YX,MS,BF,BT,VZ,DH,MK
Vitaliy is showing elements of the implementation of Mascarad, reviewing
the formalism, showing results.
-Cross section for emission of real photons is strongly peaked, which
introduces difficulties in integration of it. Chosen solution is to smear
out grid points with resolution.
-Cutoff: 850 MeV for hard photons, 10 MeV soft photon cutoff. As the BLAST
resolution is on the order of 30 MeV, question is how sensitive the
results are with respect to a variation of the low-energy cutoff.
-Energy spectrum of emitted photon peaked at low energy; shows some dip
near 50MeV, fades down above 500 MeV.
-Angle spectrum: Very forward peak (along incoming electron). Acceptance
scattered electrons continuous -> second photon peak more or less
continuous
-Cross section tail: vs. W shows again a dip below 0.1GeV
-Asymmetries: As expected, effects on asymmetries are 1-2%. The sign of
the correction is different for the two sectors.
-Extension for quasielastic scattering: issue of realistic missing
momentum distribution.
-Future handling of phase space and mascarad: Generate kinematic first
(dgen-white), feed it to mascarad, then blastmc+recon. Advantage that
this can be extended to new reaction channels.
-Estimate on memory and cpu requirements for full MC's.
Peter's update on GM extraction from vector-polarized elastic ed:
-Measured T20,T21,T11e with Blast; A(Q2) from world data (=4Equations).
Determine GC,GQ,GM (=3Params), for two values of Q2=0.154 and 0.248 GeV^2
-Interpolating BLAST results for these two Q2's
-At low Q2, the 8% discrepancy of A beween Mainz (Simon et al.) and
Saclay (Platchkov et al.) produces a systematic error of ~4% on GM
-Varied chi2 with respect to three params GC,GM,GQ, to find estimates and
errors.
Agenda for next week (Wednesday, 8/24/2005)
The coming meeting should serve as a preparational meeting on the
discussions with H. Arenhoevel, who is visiting us in the week from 8/29.
-Discussion of Pzz from d(e,e'd) elastic (CZ) and from d(e,e'p) (RF):
What are the values (for the same dataset), what are the systematics.
-If recrunch and analysis are ready by the time, perhaps update on GEn 2005
-Set up discussion list for meeting with H. Arenhoevel
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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