[Clascomment] OPT-IN: phi-meson photoproduction on Hydrogen in the neutral decay mode

[Daniel Carman]

						May 18, 2013


Dear Moskov and Heghine,

I have read through your paper on phi meson photoproduction and my comments are included below. 
This paper contains a very nice result, but the writing in the paper needs some attention. I
did my best to capture what I found in my comments below. My comments were based on the paper
draft dated May 6, 2013. If you have any questions, let me know.

				Regards,

				  Daniel

**********************************************************************************************
General: You are not consistent with your usage of speed of light units throughout this paper.
  I suggest that you let c=1 throughout.

Page 1.
 Author list.
  - Typo on "C. Meyer".
 Abstract.
  - Line 2. Use "The experiment was performed with ...".
  - Line 3. Use "... of the CLAS spectrometer at the Thomas ...".
  - Line 6. Use "The presented results significantly ...".
  - Line 8. Use "... mechanisms of $\phi$ photoproduction.".
 Left column.
  Paragraph 1.
   - Line 2. Use "... very interesting for different reasons.".
   - Line 4. Use "... [1], and on the other hand ...".
  Paragraph 2.
   - Line 8. Use "... valid for $\phi$ photoproduction ...".
   - Line 10. Use "... resonances, $\phi$ meson production is ...".
 Right column.
  Paragraph 1.
   - Line 2. Use "... exchange diagrams, as well as ...".
   - Line 3. Use "... baryon resonances, are more relevant ...".
   - Line 6. Ref. [18] is an older reference. Reference the most recent PDG listing.
  Paragraph 2.
   - Line 3. Use "$\phi \to K^+K^-$".
  Paragraph 5.
   - Line 7. Use "... $\phi$ photoproduction in the charged decay channel ...".
   - Line 8. Use "... of a $K^+$ and a prominent ...".

Page 2.
 Left column.
  Paragraph 1.
   - Line 2. Use "... with the $pK_SK_L$ final state ...".
  Paragraph 2.
   - Line 5. Use "... of the photoproduction cross section ...".
 Right column.
  Paragraph 2.
   - Line 18. You mention the photon beam energy correction and momentum corrections, but
     you do not mention what effects you are correcting for. This needs some clarification for
     the non-CLAS reader.
  Section III.A title.
   - Use "Reconstruction of the Final State".
  Paragraph 3.
   - Line 1. Use "... final state, we required that the ...".
   - Line 4. Use "... particles were identified by the ...".
   - Line 5. Use "... identification was based on ...".
   - Line 9. Use "... of the different ... type was chosen based ...".
  Paragraph 4.
   - Line 1. Use "... vertex was determined ...".
   - Line 3. Use "... that defined the timing ...".
   - Line 6. Use "... photon was selected by ...".

Page 3.
 Left column.
  Paragraph 1.
   - Line 2. Use "... that were designated ..."
   - Line 4. Use "... beam bunches, we applied ..."
   - Line 5. Use "... We also required ...".
  Paragraph 2.
   - Line 1. Use "... pions were required to be ...".
   - Line 2. Use "... GeV, respectively, in ...".
  Paragraph 3.
   - Line 3. Use "... decayed in the CLAS ...".
   - Line 4. Use "... particles were reconstructed ...".
   - Line 5. Use "... particles in the $\gamma p ...".
   - Line 6. Use "... - P_p)^2$, where ...".
   - Line 9. Use "... system was used to select ...".
  Paragraph 4.
   - Line 2. Use "... were applied to ...".

Page 4.
 Left column.
  Paragraph 1.
   - Line 1. Use "... a cut was applied on the ...".
  Paragraph 4.
   - Line 3. Use "The black points are the experimental data shown with the statistical
      uncertainties.". 
 Right column.
  Paragraph 1.
   - Add a comma after Eq.(1).
   - Line 4 after Eq.(1). Use "... mass, and $F$ is a fit parameter.".
  Paragraph 3.
   - Line 2. Use "... is done on an event-by-event basis ...".
   - Line 4. Use "... to weight each event ...".
  Paragraph 4.
   - Line 3. Use "... of the CLAS detector response.".
   - Line 6. Use "... [14], which describes well ...".
  Paragraph 5.
   - Line 2. Use "Pomeron".
   - Line 3. Use "... $\phi$ production is parameterized by the ...".
   - Line 5. Missing units on $\beta$.
  Paragraph 6.
   - Line 1. You begin the sentence with the word "Initially", suggesting that this first
      attempt was to be supplanted with a more proper physics distribution. However, you
      provide no further discussion on this topic. Why not just say "The Monte Carlo events
      were generated using a uniform photon energy distribution."?
   - Line 3. Use "... was determined by fitting ...".

Page 6.
 Left column.
  Paragraph 1.
   - Line 1. Use "... of simulated events ...".
   - Line 3. Use "... by assuming a binominal ...".
   - Line 4. Use "... for the detection and ...".
   - Line 3 after Eq.(4). Use "... corrections are on the order ...".
   - Line 4 after Eq.(4). Use "... and are included into the statistical ...".
  Paragraph 2.
   - Line 2. Use "... acceptance were binned in two dimensions.".
   - Line 3. Use "$\cos \theta_{cm}$" to be consistent with usage elsewhere in paper.
  Paragraph 3.
   - Line 2. Use "... were obtained ...".
   - Line 3. Use "Events were selected ...".
   - Line 4. Use "... one particle was missed it was ...".
   - Line 5. Use "The efficiencies were obtained ...".
   - Line 6. Use "... efficiencies were obtained as a function of the ...".
   - Line 7. Use "... of the detected ...".
   - Line 9. You make a statement here about detector inefficiencies being accounted for
      by GSIM. Something doesn't make sense. GSIM does not include detector inefficiencies.
      It assumes all detector elements are 100% efficient. I thought up to this point in the
      paragraph that you were talking about detection efficiency (the probability that if a
      particle enters the active volume of a detector and you get a recorded signal) and not
      acceptance, which is mostly a geometrical effect. Please make yourself clearer here. How
      do you account for detector inefficiencies, specifically that associated with the strong
      azimuthal angle dependence in the TOF paddles at large angles for minimum ionizing
      particles.
  Paragraph 4.
   - Line 1. Use "The fiducial cuts were applied ...".
   - Line 3. Again I am not certain here if you mean efficiency or acceptance.
 Right column.
  Paragraph 1.
   - Line 6 after Eq.(5). Use "... is the branching ratio for the decay $\phi \to K_SK_L$.".
   - Line 7 after Eq.(5). Do not use subscript "phi" on yield indicies. This is a notation change.
  Paragraph 2.
   - Line 1. Use "... was obtained using the ...".
   - Line 2. The discussion in the second sentence about the linear dependence of the normalized
      photon yield on the beam current is not at all clear to me. In fact, I cannot imagine
      what you are talking about. Given that the correction factor is sizeable, I think this
      discussion needs clarification of what the issue was and how you corrected for it. I have
      not read about such a correction in any of the other g11 papers.
  Paragraph 3.
   - Line 1. Use "... it was required to have ...".
   - Line 2. Use "... within the $\pm$2 ...".
   - Line 5. Use "... events was corrected for ...".
   - Line 8. Use "... correction was found to be ...".
   - Line 9. Use "... and was obtained ... of the $\phi$ meson yields ...".

Page 7.
 Left column.
  Paragraph 1.
   - I cannot make sense of what you call the "time window" correction. I think this discussion
     needs some clarification.
  Paragraph 3.
   - Line 2. Use "... was estimated from ... of the $\phi$ mass ...".
   - Line 4. Use "... subtraction was estimated ...".
   - Line 5. Use "the uncertainties of the fit parameters and on average was on ...".
  Paragraph 4.
   - Line 1. Do you mean low efficiency or low acceptance?
   - Line 2. Use "... cut was applied ...".
   - Line 3. Use "This cut was applied ...".
   - Line 5. Use "... of this cut was estimated ...".
   - Line 7. You say "efficiency cuts" but I think, again, that you are speaking of acceptance
      cuts.
   - Line 8. Use "The systematic uncertainty was estimated ... as the standard deviation ...".
   - Line 10. Use "... cut was about 6\%.".
  Paragraph 5.
   - Line 2. Spurious "the" on this line.
   - Line 3. Use "This factor was obtained ...".
  Table II.
   - Caption. Use "systematic uncertainties".
  Paragraph 6.
   - Line 1. Use "As mentioned in Section III D, a cut was applied ...".
   - Line 3. Use "... cut was determined ...".
   - Line 5. Use "... uncertainty was estimated ...".
   - Line 9. Typo on "greater". Also I am confused why you see variations of up to 30%
      when you vary you minimum acceptance cut. If you see variations up to 30%, then how
      can the systematic assignment not be 30%. Something is not understood if such small
      variations in your cuts give rise to fluctuations in your results this large. Please
      explain and clarify.
  Paragraph 7.
   - Line 1. Use "... 7.7\% was obtained ...
   - Line 2. Use "... of the cross sections for ...".
 Right column.
  Paragraph 3.
   - Line 1. Use "... cross section for $\phi$ meson ...".
   - Line 2. Use "... was measured ...".
   - Line 3. Use "... \cos \theta_{cm}$ for different ...".
   - Line 4. Use "... was also measured as ...".
  Paragraph 4.
   - Line 1. Use "... were obtained ...".
  Paragraph 5.
   - Line 7. Use "... of $\phi$ photoproduction.".
   - Line 12. Use "... values of $t$. This is indicative of the possible ...".
  Paragraph 7.
   - Add a period at the end of Eq.(6).
   - Line 4 after Eq.(6). Use "... E_\gamma$. In forward angle $\cos \theta_{cm}$ bins,
       corresponding to the low-$t$ region, ...".
  Experimental Results.
   - Why are there no theory curves shown with your data? Even if this paper is just an archive
     of results, it should have some input from available theoretical models.

Page 8.
 Fig. 7 caption.
  - Line 1. Use "... bins in the ...".
  - Line 2. Use "... CLAS (2013) ...".
  - Line 3. Use "... of the $\phi$.".
  - Line 5. Use "systematic uncertainties".

Page 9.
 Fig. 8 caption.
  - Line 1. Use "... bins in the ...".
  - Line 2. Use "... CLAS (2013) ... of the $\phi$.".
  - Line 4. Use "... CLAS (2000) ... of the $\phi$ meson.".
  - Line 5. Use "systematic uncertainties".
 Left column.
  Paragraph 2.
   - Section C title. Use "Total Cross Section".
   - Line 1. What you have here isn't a proper sentence. How about "To determine the
       total cross section, we fit the ...".
   - Line 3. Use "The extracted values of the differential ...".
   - Line 4. Use "... which effectively ...".
 Right column.
  Paragraph 1.
   - Line 7. Use "... 2.3 GeV just as observed in the charged-mode ...".

Page 10.
 Fig. 9 caption.
  - Line 3. Use "systematic uncertainties".
 Right column.
  Paragraph 1.
   - Line 1. Use "... sections for photoproduction ...".
   - Line 5. Use "... mechanism of $\phi$ ...".
   - Line 6. Use "... from an exponential ...".

Page 11.
 Fig. 10 caption.
  - Line 3. Use "systematic uncertainties".
 Left column.
  Paragraph 1.
   - Line 2. Use "... estimate the relative contribution ..".
   - Line 3. Use "... exchanges. The presented data ...".
  Paragraph 2.
   - Line 1. Use "... of the differential cross section ...".
   - Line 2. Use "... at the forward limit shows a ...".
   - Line 3. Use "... as was observed previously in photoproduction ...".
   - Line 5. Use "... explanations for this local ...".
   - Line 7. Use "... with $\Lambda(1520)$ production ...".
   - Line 8. Use "... as was proposed in Refs. [12,15,16,27].".

Page 12.
 Fig. 11 caption.
  - Line 2. Use "systematic uncertainties".

Page 13.
 Fig. 12 caption.
  - Line 2. Use "systematic uncertainties".

Page 14.
 Fig. 13 caption.
  - Line 2. Use "... as a function of the photon beam ... statistical uncertainties.".
  - Line 3. Use "... CLAS (2013) data in the neutral decay mode.".
  - Line 6. Use "... data, and the filled squares ... systematic uncertainties".

Page 15.
 There are problems with the format and page number of a number of the references. Please
 verify that I have not missed any. Note, the standard format is to list just the first page
 of the published article, not a page range.
 [1]. Page 998.
 [2]. Page 157.
 [3]. Page 237.
 [4]. Page 655.
 [12]. This was published as PRC 68, 015203 (2012)
 [15]. Page R2993.
 [18]. Use most recent PDG.
 [20]. Format problem.
 [22]. Page 3150.
 [24]. Page 60.
 [25]. Format problem.
 [26]. Page 213.
 [28]. Should be "B.A. Mecking".
 [43]. Typo on "Mellon".