Kinematic Corrections users,
I've looked at the discrepancy I thought might be in the proton
right theta correction, but the dip is 0.06 degrees and there are
0.1 degree deviations in the electron Left at about 60 degrees,
so this would be like splitting hairs to worry about. I see no
substantial deviations anywhere and would conclude that the
kinematic corrections with respect to ep-elastic are Done.
For finalized distributions, I would recommend using only
electrons between 25 and 75 degrees and positive
particles less than 67 degrees. Anything outside of these
boundaries, edge effects are significant and deviate
substantially from showing any resemblance to elastic
kinematics.
-eugene
Quoting Michael Kohl <kohlm@mit.edu>:
> Hi,
>
> below are the minutes of this week's analysis meeting.
> We meet again on Wednesday July 05, 2006 at 13:30 at Bates.
>
>
> Minutes
> -Pion electroproduction from hydrogen (Aki, see ppt)
> +p(e,e'pi+)n, p(e,e'p)pi0 yields and single+double spin asymmetries
> +Comparisons with MAID2000, MAID2003, DMT2001
> +Montecarlo yields of MAID2003 in each sector separately normalized
> to data, same normalization applied to MAID2000 and DMT
> +Yield difference between left and right sector 30-40% (eright
> higher)
> +piplus channel: good agreement between data and MC for beam-,
> target- and beam-target asymmetries
> +pi0 channel: seemingly large background from elastic radiation tail
> (ca. 50% of yield within missing mass cut), however asymmetries
> agree with MC for pure pi0 production. If there is significant
> elastic radiative background, (double) asymmetries would be shifted
> towards negative values
> +Shape of radiative background distribution in missingmass^2
> spectrum
> could/should be sampled with elastic event selection (impose
> coplanarity and theta-angle correlation)
> +Shape of radiative background distribution in missingmass^2
> spectrum
> could/should be simulated with Mascarad
>
> -ep elastic update (Adrian, not discussed today, see gif's)
> +Included spin angle map bin-by-bin
> +will evaluate systematic error from Q2 difference electron vs.
> proton
>
> -ep quasielastic followup (Adam, not discussed today, see ppt)
> +applied EG's momentum corrections
> +Displays p_e - p_e_calc after correction, overlayed total and
> pm<0.1
> +Quality of correction is better in quasifree limit. Remaining
> discrepancy likely due to angle offset, still to be accounted for
>
> -Miscellaneous:
> +EG's kinematic corrections, final version needed
> -EG to arrive today, work with VZ on simulation
> +MS resumes work on time calib
> -Problems with cosmics/flasher calib for
> 2004 hydrogen/ 2005 deuterium will be fixed
> -Recrunch on top to finalize e,e'n analysis
>
> +Richard/Elba meeting:
> -Isoscalar/isovector form factors: Extraction from BLAST with
> identical binning in all channels -> EG,VZ: what's the binning ->
> CC,AS extract GEp,GMp; AD,RF extract GEp,GMP; MK extract GM with
> same binning, upper Q2 limit by GMn (using Cerenkov)
> -Two-photon effects, Afanasev calculating
> -Remark that Jlab experiment will likely not give definitive
> answer,
> better use storage ring with high positron intensity
> -Proposal for Desy PAC Oct 12-13, 2006, J. Arrington interested
> -Positrons available at Doris
> +Meeting with Bonn group on July 28, 2006, MK preparing agenda
> -Two-photon physics should also be generally discussed, to what
> extent possible in Bonn (no positrons)
>
> +Blast collaboration meeting on Friday 7/14 at Bates, will send out
> preliminary agenda soon
>
> +Proton GEp/GMp draft reviewed by MK, back in hands of CC/HG
> +MK currently reviewing T11 draft; for this purpose, I had a long
> conversation with T.W. Donnelly on Tuesday. We agreed that it is
> important to verify the expressions for the polarization
> observables used in the draft. In particular, it is important to be
> clear about signs (most importantly for T21 and T11), coefficients
> (from normalization of form factor definitions), factors of i
> (Madison convention), etc. Donnelly's review article(s) are
> reliable
> references. Problems only occur when comparing one reference using
> one set of conventions with other references using other
> conventions. I'm in the process of finding relations between
> Donnelly's nomenclature in the 1984 review withI. Sick (F_i's for
> form factors and R_i^j's for polarization observables) and commonly
> used ones such as the G's or T_ij's.
>
>
> Best 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 | |
> +-------------------------------------+--------------------------+
>
>
>
>
>
--------------------------------------------------------------------------
Eugene Geis
PhD Student, Physics Department, ASU
Research Affiliate, MIT-Bates Laboratory of Nuclear Science
eugene.geis@asu.edu
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http://quickreaction.blogspot.com
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