[Clascomment] OPT-IN:Precision measurement of g1 of the proton and the deuteron with 6 GeV electrons

[Reinhard Schumacher]

Hello Yelena et al.,

I have read your draft paper "Precision Measurements of g1 of
the Proton...Electrons."  It is very evident what a careful job you
have done with this work, and the reader gets the feeling that the
results are reliable.  As a non-specialist in this area I don't have
too many comments, but it do have a few.  Also, there are some issues
with wording and figure clarity that I will list.

Reinhard
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page 2, near the bottom, 10 lines up:  What do you mean by "relatively
larger" scattering angles?  Relative to what?  You presumably mean
relative to the previous data set, but its not so clear.  

page 4, line 4:  your analysis package is not "the CLAS standard"
because there is no such standard package.  Maybe say "...with a well
tested CLAS analysis package."  

page 4, last line:  you say "seven" additional cuts, but actually you
list "eight".  

page 7, Eqs 5 and 6:  Here it occurs to me that you have not told the
reader much (anything?) about the polarization of the deuterium.
Since it is a spin 1 particle, there can be both vector and tensor
polarization.  I suppose that the tensor component is not going to
contribute to the spin asymmetry you are measuring, but I don't know
for sure.  You might want to add a line about this somewhere.  

page 11, Fig 6:  Wow, this figure is of terrible quality.  Need to
replace it with something that doesn't look like it was drawn with
crayons.  

page 12, 4 lines from bottom:  you speak of the "second term in Eq
13".  To me, "terms" are equation elements separated with + or -
signs.  I would suggest calling this the "second FACTOR in Eq 13".  To
me, a factor is a multiplicative equation element.  

page 13, line 3:  again, I suggest "term" --> "factor"

page 13, Eqs 18 and 19:  Problem with significant figures.  If you
give the uncertainty as given, you need to add a digit to the actual
values.  

page 16 near top: remove doubled comma.

page 19, Fig 9:  What a horrible figure to show off your data!  I
cannot tell the new and the old data apart:  need better symbols.
Also, use different colors to set them apart.  Get rid of the crayon
effect.  Also, for my taste I think you are binning your results too
finely.  Your error bars are still rather big, and I would not believe
any of the structure that happens on the scale of one (present) bin to
the next.  I would rebin/combine the results by at least a factor of 2.

page 19, 3 lines from bottom:  use "The dip CAN be understood..."

page 19, last paragraph:  I don't understand what you are saying about
a downward trend near W=1.23 GeV and the "dip".  It looks more like a
rise from a threshold.  A very naive question:  WHY don't you see
anything below W of about 1.2 GeV?  Is there something hidden by the
zero offset?

page 20, Fig 10:  Again, you need a crisper version of the figure.

page 21, Fig 11:  Again, a crisper figure needed, and again, to my eye
the data ought to be rebinned by about a factor of 2.

page 22, Fig 12:  same comment as above.  The CLAS data should show up
better than as a black blob.

page 23, Fig 13: same comment as above.  Also, the arrows pointing to
the axis are quite hidden in the forest of error bars.

page 24, references:  consistently use [CLAS Collaboration] without
the "The"

page 27++: will people really want to take all this tabulated data
from the publication?  You may be giving "TMI" (too much information)
here.  You could consider leaving out the tables.  In any case you
SHOULD point the reader to the CLAS database of data, properly cited
in your references.  And indeed, you then need to submit all your
tabulated results to the keepers of that database.