[Clascomment] OPT-IN: Deep exclusive pi+ electroproduction off the proton at CLAS

[Reinhard Schumacher]

Hello Kijun et al.,

I have read your draft paper "Deep exclusive pi+ electroproduction off
the proton at CLAS" with interest.  It seems to be in pretty nice
shape.  My comments, requests, and suggestions are given here.


page 1 line 31 and 33: would it not be more accurate to say in both of
these places "...effectively represents the INVERSE OF THE transverse
size of the..."?

page 1 line 42: here and many other places your references are out of
order.

page 3 line 60: here I have a request that you add a reference to the
CLAS-related "scaling" article for hyperon photoproduction published
last year by me and Misak Sargsian.  Use "...in deuteron
photodisintegration [21-24], and also in hyperon
photoproduction~\cite{Schumacher:2010qx}."

\bibitem{Schumacher:2010qx} 
  R.~A.~Schumacher and M.~M.~Sargsian,
  %``Scaling and Resonances in Elementary K^+ Lambda Photoproduction,''
  Phys.\ Rev.\ C {\bf 83}, 025207 (2011)
  [arXiv:1012.2126 [hep-ph]].
  %%CITATION = ARXIV:1012.2126;%%

This article supports the point you are making in this paragraph.


page 4 line 54/55:  it would be more correct to say "...identified by
its SQUARED missing mass,..."

page 5 line 27: I don't understand the point of Fig 4.  What are you
trying to prove by showing this figure?  Is the reader supposed to
worry that there is a "tail" of some sort that you are cutting away?
What is this tail?  As it stands now, this figure is a red flag to the
reader that something is not totally under control.  I think you send
another sentence of explanation, or drop this figure.

page 5 Fig 6 caption:  use "1.427+-.025 GeV"

page 5 Fig7: the red band is said to show "bad" TOF counters, but to
me the events inside this band look OK.  If I (and others) are missing
something, make it more explicit.

page 9 Fig 11: to make the grammar and meaning parallel, don't you
want to say "...and by the GENEV and GSIM simulation..."?

page 13 Fig 13 caption:  use "The blue solid POINTS show..."

That all for now, and good luck with the rest of the process,

Reinhard Schumacher