Hello Michael and others:
My former student Feng Xiong did a lot of work implementing POLRAD
into our 3He analysis for the JLab experiment. You may want to
take a look
at his thesis (Joanne Gregory should have copies) which might be useful.
Haiyan
On Tue, 9 Aug 2005, Michael Kohl wrote:
> Agenda:
> 1)Renee: news about hPz
> 2)Pion production: Review of N-Delta analysis, inclusive p(e,e'), and
> exclusive p(e,e'pi+), p(e,e'p)pi0, p(e,e'n)pi+. Runlist, event
> selection, yields vs W,Q2,thcms;time and experimental asymmetries.
> Status of MC: MAID + ep elastic, radiative effects (YX,AS,TF)
> 3)On the meeting structure
>
>
> Attending RF,DH,KD,JC,PK,VZ,CG,YX,CZ,AS,MS,MK.
>
> 1) Renee's update on hPz extraction for 2005
> R. verified (and demonstrated!) that the used cuts are valid for the 2005
> data. Fitting hPz at lowest 0.1<Q2<0.2 for pm<0.15 yields left-right
> consistent result around 0.47. Still, hPz exhibits Q2 dependence. If
> attributed to a deviation of the proton form factors from the
> dipole, question is how much the form factor ratio should be changed in MC
> in order to agree with the measured asymmetries.
>
> 2) Yuan showed us again the event selection for (e,e'pi+)n, (e,e'n)pi+ and
> (e,e'p)pi0 and corresponding asymmetries. There is a discrepancy between
> MAID-MC based on DGen and MAID-MC from Aki which agrees better with
> the data. Aki suspects a phi->phi+180-type error in DGen which may cause
> sign changes of one or more response functions. YX is working on MAID
> implementation.
> On the validity of MAID in BlastLib, there should be references available
> by Shalev Gilad (Hall C experiment) and also from A. Bernstein or Sean Stave
> to compare with. The MAID version in DGen evaluates pion production cross
> sections from first principles, so there is in principle the danger that
> it disagrees with what the website would predict. Sean earlier created big
> tables with MAID results covering the phase space of his experiment at
> Mainz. We should have something similar for BLAST and interpolate (like we
> do with Arenhoevel's electrodisintegration). This is faster and more
> reliable, I guess. I will meet Lothar Tiator in September.
> Tavi is working on implementing POLRAD into generator. POLRAD, originally
> for DIS, accounts for polarization-dependent radiative effects, also of
> the produced pions. It needs MAID cross sections (or transition form
> factors) for input. Effect on asymmetries can be large, as much as 40% (!)
> compared to the very small effects in elastic scattering (~1%).
>
> 3) It was raised wether and if so, how the structure of the analysis
> meeting should be changed in order to be attractive and useful.
> -The analysis meeting shall provide a forum for discussion and scientific
> discourse
> -The analysis meeting differs from the three-monthly collaboration
> meeting in the sense that the latter is pure collection of results
> without discourse while the former has focus on discussion, too. The
> analysis meeting prepares for the collaboration meetings.
> -The BLAST experiment is more than the sum of its proposals. The meeting
> shall locate and make available synergistic effects. One's result can be
> very useful for another one's analysis. Examples are manifold like hPz,
> Pzz, spin angle, kinematic corrections, etc. etc.
> -The meeting offers practise for the student in presentations
> -It is feedback to everyone's analysis - one should not only notice at the
> time of a collaboration meeting if one is on a wrong track
> -We shall have topical meetings, once per week
> -The agenda of the next meeting should be determined at the end of each
> meeting.
> -People should come prepared, especially when they are supposed to report.
> This means a few slides are in order to make things easier to understand.
> HOWEVER, presentations at the analysis meeting are no conference talks
> and are thus far more informal. Also recycled slides from earlier
> meetings may be useful for this. Renee's presentation of her progress was
> a very nice example on how it could be.
> -It was pointed out that the minutes could be rotated, but for the time
> being I'm fine with doing it.
> -I will try to keep the length of the meeting below 90 minutes.
>
>
>
> Proposed agenda for meeting on Wednesday 2005/08/17:
> -Radiative effects in the BLASTMC generator (Mascarad)
>
>
> Regards,
>
> Michael
>
>
>
-- ======================================================================== Haiyan Gao URL: http://www.tunl.duke.edu/~mep Triangle Universities Nuclear Laboratory Department of Physics, Duke University Office: 426 TUNL Office Phone: (919)-660-2622 Email: gao@tunl.duke.edu Fax: (919)-660-2634 Mailing address: 426 TUNL Building Science Drive Box 90308 Duke University Durham, NC 27708 =========================================================================
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:32 EST