[Clascomment] OPT-IN:Target and Beam-Target Spin Asymmetries in exclusive Ï+ and Ïâ electroproduction with 1.6 to 5.7 GeV elec trons

Sun Feb 28 15:59:03 EST 2016

DEar Peter,

Let me answer

1) You have to point out that you collected data on bound neutron

2) Up to you but I was thinking that is important to give CLAS credit
specifically that CLAS deserves
that

4)
 PI-P  NORMALIZED Chi2 SUMMARY    2/28/16   for:
 EPPI0P108 8/08/07 RAA WORLD+CLAS+BONN   08/17/12    add 17375/14772
 Q2min=   0.000 Q2max=   7.000
 Sol1-SM08K 2000 WN08(53013/25253)+162774/107078(188) JO07(0) SM05   2

   SR    TYPE  Nexp Ndta  Emn  Emx   Q2mn   Q2mx   Amn    Amx  Ch1
  GA(01)  DL     2     2 1150 1600   0.40   0.40   3.6   3.7    10.    10.
  WR(81)  DSG  297   297 1253 1705   0.47   0.54   6.0  74.6   753.
  MO(79)  DSG   20    20 1285 1675   0.96   1.13  12.6  14.4    49.
  MO(78)  DSG   20    20 1285 1705   0.46   0.56  12.6  14.5    46.    .
  VA(88)  DSG  448   448 1255 1655   0.97   1.14   8.5  84.2  1009.
  BB(76)  DSG    8     8 1669 1980   1.25   1.35  10.5  31.4    16.
  BB(78)  DSG    4     4 1941 1984   1.31   1.37  13.2  22.1     0.
  GA(01)  DT     2     2 1150 1600   0.40   0.40   3.6   3.7     0.

 Nexp= 801 Ndata=  801  ChN(1)=   1883.9
                                              ChU(1)=   1883.9

GA(01):   GASKELL, PRL87, 202301(2001)
WR(81):  WRIGHT, NPB181, 403(1981)
MO(79):   MORRIS, PLB86, 211(1979)
MO(78):   MORRIS, PLB73, 495(1978)
VA(88):    VARENIKOVA, ZPC37, 251(1988)
BB(76):    BEBEK, PRD13, 25(1976)
BB(78):    BEBEK, PRD17, 1693(1978)

7) As far as I suggested, it is good to add SAID predictions

Have a nice weekend, Igor

-----
Igor Strakovsky, SAID INS The George Washington University
Tel: 571-553-8344,Skype: igors1945_2, Fax: 202-994-3001
Cell: 703-728-5627, Emails: igor at gwu.edu, igor at jlab.org

On Sun, Feb 28, 2016 at 3:24 PM, <bosted at jlab.org> wrote:

> Dear Igor,
> That is really impressive work.  I have several comments and suggestions
> for your
> consideration...
>
> 1) Abstract: You do not have en-->epi-p data.  You did not collect data on
> free but bound neutron.  One cannot possible to measure pionEPR on the
> "neutron" target you have to take into account FSI corrections to convert
> ed-->epi-pp into en-->epi-p. There are no FSI calculations for pionEPR.
> FSI for asymmetries could be small but
> still unknown. CHANGED to "...kinematic bins
> for $\pi^+$ and 35,000 bins for $\pi^-$ production."
>
> 2) Abstract: Most of "previous world data" are CLAS measurements
> (according to the SAID database - CLAS collected about 85% of the world
> database) and I would  punch this fact. NOT DONE (doesn't seem appropriate
> to me).
>
> 3) Abstract: I do not think that last phrase is necessary here.  No
> resonance couplings are presenting in the manuscript. CHANGED to
> "When combined with cross section measurements,
> the present results will provide powerful constraints
> on nucleon resonance amplitudes at moderate and large
> values of $Q^2$, for resonances with masses as high as 2.3 GeV."
>
> 4) line 16: your list of pi- measurements is uncompleted, check the SAID
> database which has all available data. I cannot seem to get there: when I
> click on "data Base" on
> http://gwdac.phys.gwu.edu/analysis/epr_analysis.html
> nothing happens. Can you send any pi- reference you consider essentail.
> Meanwhile, I've change to say "references include..."
>
> 5) line 45: I am not sure that one can possible to prove that your
> treatment for en-->epi-p is good enough.  We published several PRC papers
> for pionPR analyses which allows to get gn-->pi-p from CLAS (g10) and
> MAMI-B gd-->pi-pp measurements. inSpire can give you appropriate refs.
> ANSWER: Text has been changed to be very
> careful to say that we present measured asymmetries on deuteron target. No
> neutron response functions are extracted in this paper.
>
> 6) line 143: How is about a neutron-detection efficiency?  How your took
> it into account? ANSWER: There is no need to account for any efficiencies
> in asymmetry measurements (the efficiency cancels in the ratio)
>
> Let me suggest to add more curves to your data-plots using EBAC and SAID
> predictions which will obviously benefit this manuscript.
> ANSWER: The JANR fit is from the EBAC group (Inna). I tried using SAID but
> ran into difficulties, and decided two curves were enough to illustrate
> the point that new fits are needed now that we have more data.
>
> BTW I am not sure if I am familiar with JANR treatment but MAID07 does not
> fit available g*n-->pi-p data (they used some relationships between p and
> n targets) ANSWER: Inna (JANR) did not consider pi- production. She only
> does
> pi+ and pi0.
>
>
>
>
>
>
>
>
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