OPT-IN:Determination of the Beam-Spin Asymmetry of Deuteron Photodisintegration in the Energy Region E_gamma = 1.1 -ô 2.3 GeV

[Reinhard Schumacher]

Hello Nick et al.,

Your paper "Determination of the Beam Spin Asymmetry...GeV" is long,
detailed, well-written, and sure to get accepted in Phys Rev C.  I
have read almost the whole thing, and have just a few comments and
questions.

line 83: The two review article references here are pretty ancient.
Is there nothing newer about dimensional scaling than 1994?  I would
think Misak knows of some more up to date references.

Figure 1: The two halves of the figure are totally redundant.  That
is, the same information would be conveyed if you just use Part (a).
Also, in the caption you list reference 48 as "private communication"
from Misak.  That is not appropriate, since he is a co-author of the
paper, so just remove it.

Footnote after line 272:  Why is this here, rather than just a part of
the main text?  It seems unnecessary. 

Figure 2: the fine lines of the arrows that help label the figure are
invisible in my printed copy.

Figure 4+: on the computer screen, the axis labels of this figure are
OK. However, when I printed out the paper, this labels turned into
gibberish.  You might want to investigate this issue, since for me it
affected all of the following figures:
4, 7, 8, 9, 13, 14.

line 539++: The Q-value method of separating background is not an
obvious choice for your analysis.  The method was meant for reactions
with multiple final state particles, for which the kinematic
correlations among variables are impossible to capture with basic one
and two-dimensional binning.  However, your reaction is a single-arm
reaction wherein you detect only the proton.  You could have done a
much simpler analysis by binning the missing mass variable in each
kinematic bin as per Figure 8, and then fit a Gaussian and a
background of your choice to "statistically separate" signal and
background.  There are no hidden correlations in the case of your
reaction.  Using the Q-value method seems like overkill.  Can you
please address this question with a short paragraph in the paper?
Otherwise the astute reader may question your choice.

Line 773++: It is good to be exhaustive in exploring your systematic
uncertainties, but I think you overdid it by having too many very
short subsections.  I recommend that you combine similar ones into
longer sections.  You could combine A and C under the heading
"azimuthal angle" and combine F, G, and H under the heading "Reaction
selection cuts".

Line 1017: It reads a bit bizarrely when you "like to thank late
Prof. Berman", because he is dead.  He cannot accept your thanks.
Maybe say "like to express our gratitude to the late Prof. Berman..."

That's all for now,
Reinhard