[Clascomment] OPT-IN:Differential cross section of gamma n --> K+ Sigma- on bound neutron with incident photons from 1 to 3.6 GeV

[Daniel Carman]

Dear Sergio et al,

I have read through your manuscript draft for KSigma photoproduction
dated Nov. 19, 2009 and have a number of comments. I present them in 
the order that I found them, making no attempt to separate physics 
comments from grammar/style comments. Please let me know if you have 
any questions on what I have included. I seems that you will try to
submit this to PRL. I am pretty sure it will not be accepted by them,
especially given the new standards that they have set in place. This data, while new, is still just an archival paper of some data points
with very little of general interest for the broader community. You should seriously reconsider your choice here.


				Regards,

				   Daniel

**********************************************************************
General: 
  - Be consistent with your ordering of the meson and baryon in the
    reaction listing. Sometimes you use MB and sometimes BM. I prefer
    to list the meson first, i.e. $K+\\Sigma^-$.
  - You should provide a reference for the neutron detection efficiency
    determination and also state the efficiency range vs. Pn.
  - I do believe you have essentially lifted paragraphs 2 and 3 from
    an earlier CLAS paper that I wrote. Not cool cutting and pasting
    from someone else\'s work without citation.

Page 1. 
  Title.
    I suggest \"... on bound neutrons ... from 1.15 to 3.55 GeV\".
  Abstract.
    Line 1. Use \"... measured with the CLAS ...\".
    Line 2. Use \"... 1.15 and 3.55 GeV\".
    Line 5. Awkward. I suggest \"For $E_\\gamma > 1.8$~GeV, a clear ...\".
    Line 7. Use \"... $t$-channel production mechanisms.  These data can
      be used to constrain ...\"
  Left column.
    Paragraph 1.
      Line 10. Opening quotation marks are incorrect.
      Line 15. I suggest to make the sentence beginning \"The effective
        degrees of freedom ...\" start a new paragraph.
      Line 18. Use \"... interactions that give rise ...\".
      Line 29. Use \"... quark-diquark models.\".
  Right column.
    Paragraph 1.
      Line 4. Use \"... at higher masses;\".
      Line 14. Use \"... that decay into ...\".
    Paragraph 2.
      Line 7. Use \"... spectra, the $t-$ and ...\".
      Line 8. Use \"... are also necessary in ...\".
    Paragraph 3.
      Line 2. I suggest \"... has been published in recent years ...\".
      Line 3. Use \"CB-ELSA\".
      Line 5. Reference McCraken paper (which will be posted soon on
        the archive and submitted). It is now the CLAS standard and 
        has photon energies up to ~3.8 GeV.

Page 2.
  Left column.
    Paragraph 1.
      Line 3. Ref.[17] is not a coupled-channels model. It is a single
        channel isobar model.
    Paragraph 2.
      Line 2. Use \"In particular, for $Y$-photoproduction ...\".
      Line 3. Use \"... the neutron, one can ...\".
      Line 4. What do you mean by \"triplet\"? This sentence needs some
        attention.
    Paragraph 3.
      Line 11. Check the flux number. 10**8 seems a bit high.
    Paragraph 4.
      Line 3. Use \"... coils that defines six independent sectors.\".
    Paragraph 5.
      Line 2. The sentence beginning \"The field intensity was run ...\"
        comes out a bit awkwardly. How about \"The data under analysis
        in this work was acquired with roughly equal numbers of
        triggers at torus settings of 2250~A (60\\% of full field) and
        3375~A (90\\% of full field).\"?
      Line 6. Use \"... charged particles, ...\".
    Paragraph 6.
      Line 1. Use \"... kaon, and the pion ...\".
      Line 2. Use \"... 100\\%), ...\".
      Line 4. The sentence beginning \"The energy and momentum ...\"
        reads a bit awkwardly. How about \"The energy and momentum of 
        each charged particle were corrected for the mean energy lost 
        prior to reaching the DC and for possible misalignments of the
        tracking system and distortions of the torus magnetic field.\"?
  Right column.
    Paragraph 2.
      Line 3. Use \"contaminate\".
      Line 10. I suggest \"In addition, the reconstructed kaon reaction 
         vertex was ...\".
    Paragraph 3.
      Line 6. Awkward construction. How about \"thus, the 
        identification of slower neutrons required ... a set of
        dedicated routines in order to obtain their correct time of
        flight and to calculate their $\\beta$.\"?
    Paragraph 6.
      Line 6. I suggest \"... the $\\Sigma^-$ appears on ...\".
      Line 8. Use \"second-order\".

Page 3.
  Left column.
    Fig. 2 caption.
      Line 2. Use \"The solid line ...\".
    Paragraph 1.
      Line 5. Use \"deuterium\".
  Right column.
    Paragraph 1.
      Line 5 after Eq.(1). Use \"is Avogadro\'s number\".
      Line 7 after Eq.(1). Use \"low-intensity\".
      Line 14 after Eq.(1). Use \"... from the low and high ...\".
      Your statement regarding how the photon flux is determined
      really doesn\'t paint a clear picture. I think it would be 
      relevant to reference the appropriate work for the interested
      reader (e.g. CLAS-Note 2005-002).
    Paragraph 2.
      Line 2. Use \"... from the photon flux ...\".
      Line 5. Use \"... and the Monte Carlo ...\".
    Paragraph 3.
      Line 6. Use \"At a photon energy ...\".
      Line 10. Use \"... energies, where the dominant ...\".

Page 4.
  Right column.
    Line 10. Use \"... operated the Thomas Jefferson ... 40150 during
      this work.\".

Page 5.
  Fig. 3 caption.
    Line 2. Use \"... the statistical uncertainty ...\".