[Clascomment] OPT-IN: Study of Cascade* Photoproduction from Threshold to W = 3:3 GeV

[Daniel Carman]

Dear Johann, Ken, John, and Dennis:

I have read through the draft of your paper on Cascade photoproduction from analysis of
CLAS data and include my comments below. If you have any questions, let me know.

Regards,
Daniel
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Page 1:
 - Line 12. Use "... and upper limits for the total cross sections have been ...".
 - Line 13. Use "... of the ground state $\Xi^-(1320)$ and first excited state $\Xi^-(1530)$ ...".

Page 2:
 - Line 25. Typo on "correspondence".
 - Line 34. Use "... first resonance region with negative ...".
 - Line 38. Use "... whereas the $\Xi(1530)$ ...".
 - Line 40. You state several times that the Cascades are expected to be easily isolated as a
    peak in the mass spectrum. This statement is certainly misleading. What you see depends
    on the production cross section, the signal/background ratio, the experimental resolution,
    and a host of other factors. I suggest that you re investigate the statement here and the
    several other places that you make a similar claim to improve the language a bit.
 - Line 47. You state that the total cross section is expected to level off. Why do you make
    this claim as it is certainly not obvious and is important for what you show later? Certainly
    a reference is necessary here.

Page 3:
 - Line 52. Typo on "excited".
 - Line 52. Use "... K^+ Y$, followed by ...".
 - Fig. 1 caption. Unclear as written. How about "... of the (left) $\Xi^-$ ground state and (right)
    excited states through decay of an ...".
 - Line 54. Need a reference for the OZI rule.
 - Line 57. Use "... photoproduction of excited $\Xi$ states.
 - Line 64. Use "The CLAS detector ...".
 - Line 67. "To allow for the high luminosity of the beam's 60-65 nA current, ...". This wording is
    awkward.
 - Line 69. Use "... that surrounded the outside ...".

Page 4:
 - Line 74. Use "$K^+$.
 - Line 74. "In this analysis, events where ...". This is not a proper sentence. Please rewrite.
 - Line 79. Use "... $K^+$s became possible".
 - Line 80. Use "The mass of each charged particle can ...".
 - Line 85. Use "$K^+K^+$".

Page 5:
 - Fig. 2. You need to add a sentence or two explaining the contributions to the background beneath
    your K+ peaks. Also, you should give the centroid and widths of your Cascade peaks. Why is the
    width of the Xi(1530) so much wider than the ground state? Is FWHM is ~9 MeV, so the width
    should be dominated by the resolution of CLAS. Perhaps you should state what the MM resolution
    of CLAS actually is.
 - Fig. 2 caption. Line 1. Use "$K^+K^+$". Also you should state in the caption that this plot was made
   summing over all W and all angles.
 - Fig. 3. You have not stated what g11 is. Also, you did not say anything about the cross section for
   the 1535 in the text.

Page 6:
 - Line 99. Use "$N^*$" and "$Y^*$".
 - Line 108. I suggest adding "Thus the overall systematic uncertainty for these measurements is 8.8\%.".
 - Line 109. Use "$K^+K^+$".
 - Line 110. Use "... on the total production cross section ...".
 - Line 113. This sentence should not begin a new paragraph.
 - Line 117. This paragraph "The ratio of the ..." is a complete orphan that seems tacked on. It can be
    eliminated.
    
Page 7:
 - Fig. 4 caption. Line 1. Use "$K^+K^+$".
 - As you are trying to get this accepted by PRL, the conclusions seem to be a bit soft. I recommend that
   you try to "beef" them up a bit. What in this analysis is important enough to make this paper worthy of
   being published as a letter? Once you can crisply answer this question, make sure that your paper and
   your conclusions reflect that.

Page 8:
 - The bibliography is not written in a consistent style. You should look at PRL and match your style to
    what they use.
 - You should list collaboration names associated with the papers. In particular, all papers from CLAS should
   include "(CLAS Collaboration)" after the "et al.".
 - Ref. [2] is incomplete.
 - Ref. [8] title is not complete. Problems with the reaction listings.
 - Ref. [11] has a spurious "0" after "$\Xi(1690)".
 - Ref. [12] has a spurious "*" after "135 GeV/c".
 - Ref. [14] has problems with the title formatting.