[Clascomment] OPT-IN:Di erential cross sections and spin density matrix elements for the reaction gamma p --> phi p

[Daniel Carman]

						April 22, 2013


Dear Curtis et al.,

I have read through your paper on phi photoproduction and my comments are included
below. In general this is a well written paper that is clearly presented. I include
all of my comments below based on the paper draft dated Apr. 18. If you have any 
questions, let me know.

				Regards,

				  Daniel

********************************************************************
General:
 - You are not consistent throughout the paper with your usage of speed of light units.
   I suggest that you just let c=1 everywhere to avoid these issues.

Page 1.
 Left column.
  Paragraph 2.
   - Line 3. Typo on s definition. Should be "$s = (p_\gamma + p_p)^2$.
   - Line 8. Eliminate comma after "[9-11]".
   - Line 11. "MeV" should be in rm font.
 Right column.
  Paragraph 1.
   - Line 2. Use "... $s\bar{s}$ state, while the ...".

Page 2.
 Left column.
  Paragraph 2.
   - Line 5. Use "... a description of the event-selection ...".
 Right column.
  Paragraph 2.
   - Line 9. Spurious "the" on this line.
   - Line 12. Use "... and required a coincidence ...".
   - Line 14. Use "... the given sector. ... two-track condition required that ...".
   - Line 20. Use "... out-of-time track contamination.".
  Paragraph 4.
   - Line 5. Use "(non-strange mode).".

Page 3.
 Left column.
  Paragraph 1.
   - Line 6. Use "... setting of the CLAS torus was such that it bent ...".
  Paragraph 3.
   - Line 4. Use "... particles were kinematically fit ...".
 Right column.
  Paragraph 1.
   - Line 4 after eq(1). Use "... track hit the TOF ...".
   - Line 7 after eq(1). Use "... then computed a corresponding ...".
   - Line 8 after eq(1). Use "... cut required that ... $\Delta tof$ was within ...".
  Paragraph 2.
   - Line 1. Use "... contamination, we applied an additional ...".

Page 4.
 Left column.
  Paragraph 2.
   - Line 6. Use "... $M_{max}(pK)$, value."
   - Line 16. Use "... show mass-mass plots ...".
 Right column.
  General. This whole paragraph "In this analysis we have applied two types of cuts to ..." has a lot of
    words, but very little clear content. After all of your discussion, you then state "We keep the option
    of placing a hard cut around the $\Lambda(1520)$ mass ...". It would a much crisper discussion if you
    just clearly state what you did, not what you might do or could do.
  Eq(4). Include "GeV" units in the formula.
  - Line 3 after eq(4). Use "... hard cut are given ...".

Page 5.
 Fig. 4 caption. 
  - Line 5. Use "... 2.105~GeV, while panel (b) shows ...".
  - Line 6. Use "... 2.305~GeV. The $\phi$ ...".
 Left column.
  - Line 3. Use "... reconstructed mass, as well as cuts ...".
 Right column.
  Paragraph 1.
   - Line 1. Use "... a Gaussian plus a quartic ...".
   - Line 5. Use "... $K^-$) events and ...".
  Paragraph 2.
   - Line 15. Use "... detector volume, such as inside the drift chambers, ...".
   - Line 20. Put "MeV" in rm font.
  Paragraph 3.
   - Line 1. Use "... very effective in selecting a clean data sample ...".

Page 6.
 Right column.
  Paragraph 1.
   - Line 4. Use "... of a non-relativistic ...".
  Fig. 5 caption.
   - Line 2. Use "2.08~GeV $\le$ $\sqrt{s}$ $\le$ 2.12~GeV".

Page 7.
 Left column.
  Paragraph 3.
   - Line 4. Use "... was pseudo-randomly ...".
   - Line 6. Use "The simulation also ...".
 Right column.
  Fig. 6 caption.
   - Line 5. Add units within $\delta$ expression, "1.52~GeV".

Page 8.
 Right column.
  Paragraph 1.
   - Add a comma after eq(12).
  Paragraph 3.
   - Line 1. Use "... analysis was carried out ...".
  Paragraph 5.
   - Line 4. Use "... prevented accurate electron ...".

Page 9.
 Left column.
  Last paragraph.
   - Line 15. Use "... to the $d\sigma ... measurements are given in Table I.".
 Right column.
  - Add a comma after eq(19).

Page 10.
 Right column.
  - Line 2. Use "... elements), while the trace ...".

Page 11.
 Left column.
  Paragraph 1.
   - Line 13. The part about TCHC is not complete. You should say something like "... flip will
      occur, $t$-channel helicity conservation (TCHC) will be obeyed, and the vector meson ...". 
  Fig. 7 caption.
   - Line 3. Remove comma after "$z$-axis".
  Equation.
   - Why is the y-hat equation not numbered?
  Last paragraph.
   - Line 4 after y-hat equation. Use "... Adair frame, ...".
 Right column.
  - Line 1. Remove spurious punctuation after "as follows".
  - Add a period at the end of eq(34c).
  - Line 3 after eq(34c). Use "... of the signs [33], the Wigner ...".
  - Line 1 after eq(37c). You should not begin new paragraph with "where $\beta ...".

Page 12.
 Left column.
  Paragraph 2.
   - Line 2. Use "... application of Schilling's expression ...".
   - Line 8. Use "Eq.33".
  Last paragraph.
   - Line 11. Use "... should extend our knowledge of vector-meson photoproduction in general.".
 Right column.
  Paragraph 1.
   - Line 1. Use "Figs. 10-12 show our differential cross section results vs. $\cos \theta_{cm}^\phi$ in
       different $W$ bins with the ...".

Pages 14-16.
 - Why do your x-axis ranges go beyond -1 to 1. This is unnecessary and just adds extra white space to the
    plots.
 - Captions of Figs. 10, 11, and 12 are all mislabeled. The plots are not vs. $\sqrt{s}$ as stated.

Page 17.
 - Fig. 13 caption. Put "GeV" in rm font.

Page 19.
 Left column.
  Fig. 15.
   - What are the systematics associated with the SAPHIR data? This is relevant to understand how
     good the agreement between the two data sets is.
   - Caption. 
     - Line 2. Use "... and SAPHIR 2003 ...".
     - Line 4. Use "... on each plot and the ...".
  Paragraph 2.
   - Line 1. Use "... kinematics were mostly ...".
 Right column.
  Fig. 16.
   - What are the systematics associated with the LEPS data? This is relevant to understand how
     good the agreement between the two data sets is.
   - Caption. Line 4. Use "... on each plot)."
  Paragraph 1.
   - Line 9. Use "... Fig. 17, are supposed to ...".

Page 20.
 Fig. 18 caption.
  - Line 2. Use "...and CLAS 2000 ...".
  - Line 4. Use "... $E_\gamma$, while the current ...".
  - Line 6. Use "... data supersedes the older data.".
 Fig. 19 caption.
  - Line 2. Use "... and Daresbury 1982 ...".
  - Line 4. Use "... $E_\gamma$, while the CLAS ...".
 Paragraph 1.
  - Line 2. Use "... $\cos \theta_{c.m.}^\phi$, while Figs. 23-24 ...".
  - Line 3. Use "... These results include the hard ...".

Pages 21-23.
 - Figs. 20, 21, 22 captions. Line 2. Use "... Adair frame are shown with the ...".
 - Energy range is incorrectly listed in Fig. 22 caption. Should be 2.61 to 2.84 GeV.

Page 26.
 Left column.
  Paragraph 1.
   - Line 6. Use "... 0.25t$, where ...".
  Paragraph 2.
   - Add a comma after eq(40). 
   - Line 9 below eq(41). You state "possibly due to effects from the $\Lambda(1520).$ This statement
      confuses me as you have an explicit cut on the $\Lambda$(1520) to remove it. Are you talking about
      events that leak out of your cuts? If so, wouldn't you study what happens as you make your 
      Lambda(1520) cut wider?

Page 27.
 Left column.
  Paragraph 1.
   - Line 2. Use "... outgoing-proton, which we do not measure, ...".
   - Line 5 after eq(42). Use "... converted into the Helicity ...".
   - Line 8 after eq(42). Use "... inall three reference ...".
  Fig. 27 caption.
   - Line 2. Use "... in all three reference ...".
 Right column.
  - Line 2. Spurious listing of "R_{\phi/\omega}$.

Page 28.
 - Ref.[3] missing period at the end.
 - Ref.[4] has problematic page listing. Should be "3150 (1973).
 - Refs.[5],[7],[12]. Do not list page range. Only first page of paper.
 - Ref.[8]. Use "Phys. Rev. C {\bf 82}".
 - Ref.[25]. Should be "(2010)."
 - References get out of order after Ref.[29].
 - I could not find Ref.[30] listed in the text.
 - Refs.[31] and [32] have problematic listing of page number.