[Deeppwg] NSTAR proceedings

[GUIDAL Michel (57321)]

Hi Daria,

Some more comments in addition to Volker's and Silvia's:

*abstract, l.3:
"Data from both proton and neutron targets is required for an extraction 
of all accesible GPDs...". It is not clear to me what are the "accessible 
GPDs" ? What are the "non-accessible GPDs" ?

*introduction, par.1, l.1: "The most complete information..." might be too 
strong, there are probably things on nucleon structure which cannot
be accessed through GTMDs. "A wealth of information..." or something like 
that to be cautious.

*l-7/8: two times "the".

*par.2, l.11: "extraction of the real parts of GPDs...". Silvia pointed it 
at some other place above, here it comes again: GPDs are real.
Also, I wouldn't say that "cross-sections and double-spin asymmetries 
allow the extraction of the real part...", they are "sensitive to".
For the true "extraction", one needs more than these 2 observables.

*par.3, l.4: "the imaginary part of the GPD E". Again, GPDs are real.

*l.5: "acesSible". Also, I would remove the "however", I don't see any
contradiction with the fact that E is the least known.

*p.2, 3 lines below eq.1. "This paper..." is not very nice. "These
proceedings", "This article",...

*section 2, par.1, l.6: "electRon".

*l.8: "scintillator wall". It might be strange to call our IC made of
PbWO4 crystals "scintillator wall". "Scintillators" refer to something
else in general.

*par.2, l.7: "the recoil electron". A bit strange. "scattered electron" 
rather ?

*l.13: "stacettering" !!!

*l.14: "W>2 GeV/c2" Sometimes you use the "c" and sometimes not
(line below: "Q2>1 GeV2"); you probably have to choose and stick to one 
notation.

*l.16: "factorisation...into a hard-scattering and a soft-scattering part 
applies". You never introduced those "hard" and "soft parts". It seems
to come out of the blue...

*last sentence of par.2: "(to estimate which the same particle 
identification and distribution cuts were applied to 14ND3 data)"
sounds bizarre.

*par.3, l.1: "traget".

*Fig.2: I am not shocked by the target asymmetry. Maybe, there is
no signal indeed but still this is information. I have no
problem to leave it but no problem as well to remove it. Actually,
the overall question is what is allowed to be released according to the 
CLAS rules ?
By the way, in the caption, why do you fit the BSA and the TSA by 2 
different functions ?

*p.5, bibliography: "[5]:... PRL 99". ->"Phys.Rv.Lett."
[6]: instead of "private communication", you can probably refer
to the original CLAS proposal. This is true that I/we should publish on 
n-DVCS some day.

Amities,

Michel

***
Michel GUIDAL
Institut de Physique Nucleaire
Bat 100 - M130
91406 ORSAY Cedex
Tel: (33) 01 69 15 73 21
Fax: (33) 01 69 15 64 70
E-mail: guidal at ipno.in2p3.fr
***