[Clascomment] OPT-IN: Transverse Polarization of Sigma+(1189) in Photoproduction on a Hydrogen Target

[Reinhard Schumacher]

                                                       12-21-12
Hello Chandra and Moskov,

I read your paper on "Transverse Polarization....in CLAS" dated
12-18-12, and I have a few suggestions and corrections.  Overall, it
is nice to see that you have some useful new polarization measurements
to publish, ones that are sure to arose interest because the results
are somewhat surprising.

page 1 col 1, line 10:  here you refer to a group of references
numbered 3 to 7.  They are not all correct or appropriate.  As long as
you are citing the "main results" obtained in these reactions, you
should use

Ref (suggested order)
3  this one is OK
4  not sure why this is included,  It's not a real paper
5  OK
6  OK
7  OK
8  Add reference to CLAS Bradford 2006 paper
9  Add reference to CLAS Bradford 2007 paper
10 Add reference to CLAS McCracken paper
11 The Dey paper which is Ref 10 right now should definitely be in
this group

page 1, col 1, paragraph 2:  Twice you cite Refs 5 and 10, but here
you really need to also cite the McCracken paper.

Page 1 bottom of page:  I would make Moskov the email contact, since
his address at ODU is likely to endure longer than Chandra's.

page 2 end of first long paragraph where momentum and eloss
corrections are mentioned.  There are CLAS Notes by Williams and by
Pasyuk that should be cited to give credit to the people who came up
with these corrections.

Figure 4:  The caption is way to verbose.  A caption should ONLY tell
the reader what is shown in the figure, and all  the other information
should be folded into the main text.  

page 3 col 2, near bottom:  you use "i. e." here and elsewhere, which
is OK, but use "{\it i.e.}$ with no space after the first period.

page 4 near top:  "Therefore, the effectS due..."  add the "S".  Then,
later in the sentence, what "false asymmetry" are you talking about
here.  Unclear.

page 4, col 1, para 3:  use "...conserves parity."  get rid of
definite article "THE"

page 4, Eq. 4:  this equation is wrong.  Take the cross product of
these two unit vectors and you don't get another unit vector.  Just
divide by the magnitude.

page 4, before Eq 7:  you don't need this raft of five references to
justify the formula.  Pick one.  Anyway, any textbook on the subject
would be sufficient.

page 5, col 2, bullet point:  it makes little sense to quote a PERCENT
error on a polarization.  What if the polarization turned out to be
zero in some bin.  Would you then claim the error is 0% of zero, and
therefore vanishingly small?  No.  You should give the systematic
error as and absolute number.  If I understand what you did, using a
100% polarized Monte Carlo sample, you might say the systematic
uncertainty is +-0.05.


That is all for now.  Good luck with the paper.

Reinhard