[Clascomment] OPT-IN:Suppression of neutral pion production in deep-inelastic scattering off nuclei with the CLAS detector

[Daniel Carman]

Dear Taisiya et al.,

I have read through the draft of your paper on multiplicity ratios discussing neutral pion
suppression I include the comments from my reading below. If you have any questions, let me
know.

Regards,
Daniel
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General:
 - When you use latin abbreviations like "e.g." and "i.e.", they should be in italics font,
   "{\it e.g.}" and "{\it i.e.}".
 - It would have been better to include line numbers for the circulated review manuscript to make referencing easier, but hopefully my locators of paragraph/line are straightforward enough.

Page 1:
 - Abstract:
   - Line 1. Use "three-fold".
   - Line 4. Use "... from 25\% in carbon up to ...".
   - Line 5. Use "... is observed, suggesting an ...".
   - Line 9. Use "... for the lightest nucleus - carbon and the lowest ...".
   - Line 10. Use "... heaviest nucleus - lead.".
 - Paragraph 1. Line 14. Use "... functions (FF), which describe ...".
 - Paragraph 3. Line 1. Use "... sensitive to the in-medium ...".
 - Eq. (1). End with a period for proper punctuation.
 - Eq. (1). All subscript here are in Roman font. They should not be.

Page 2:
 - Paragraph 1. Line 6. Use "fully identified". (no hyphen with -ly words in English)
 - Paragraph 1. Line 7. Use "... with the HERMES program ...".
 - Paragraph 1. Line 12. Use "one-fold".
 - Paragraph 1. Line 13. Use "$p_T^2$".
 - Paragraph 1. Line 29. Use "... can be found in Ref.~[30].".
 - Paragraph 3. Line 9. Use "... CLAS had four types ...".
 - Paragraph 4. Line 3. Use "liquid-deuterium".
 - Paragraph 4. Line 5. "it was placed 30 and 25 cm upstream of the CLAS center". I cannot make sense
   of what you are saying here. What do the values 30 cm and 25 cm represent? You just stated in the
   previous sentence that the liquid and solid targets were separated by 4 cm. Please review.
 - Paragraph 4. Line 8. Use "... electron beam passed ...".
 - Paragraph 4. Line 9. Use "... simultaneously, first through the cryotarget ...".
 - Paragraph 4. Line 10. Use "... systematic effects were reduced ...".
 - Paragraph 5. Line 2. Use "... scattered electrons, respectively, and ...".
 - Paragraph 6. Line 7. Use "$x_{Bj}$" to match notation already used in opening paragraph.
 - Paragraph 6. Line 12. Use "... differential multiplicity ratios with 1) a total of 108 ... over $Q^2$
   and 2) a total of 54 bins in ...".
 - Paragraph 7. Line 2. Use "... a signal in both the TOF and EC.".
 - Paragraph 7. Line 6. Use "... with sector- and momentum-dependent cuts ...".
 - Paragraph 7. Line 8. Use "... layer of the EC, and a coincidence time matching between the ...".
 - Paragraph 7. Line 9. Use "... near the detector acceptance edges with non-uniform ...".
 - Paragraph 7. Line 13. Use "... the scattering event, corresponding to either ...".

Page 3:
 - Fig. 1. I do not think that the right figure showing just the background adds anything of value and
   could be eliminated altogether.
 - Fig. 1 caption.
   - Line 3. Use "The total signal plus background fit function ...".
   - Line 4. Notation change for coefficients in this line and the next.
   - Line 6. Use "... first in the range $0.3 < M_{\gamma\gamma} < 0.25$~GeV to ...".
   - Line 7. Use "... and then in the range ...".
 - Paragraph 2. Line 1. Use "... electron was identified, ...".
 - Paragraph 3. Line 2. Use "... was fit with a ...".
 - Paragraph 3. Line 6. Use "... technique that consisted ...".
 - Paragraph 3. Line 12. Use "... event-mixing technique ... in Ref.~[34].".
 - Paragraph 3. Line 14. Use "4th-order".
 - Paragraph 3. Line 18. Use "... from the integral of the Gaussian function.".
 - Paragraph 4. Line 3. Use "... normalized by the electron ...".
 - Paragraph 4. Line 8. Use "... of a percent up to ...".
 - Paragraph 4. Line 11. Use "... the field of the nucleus:".
 - Paragraph 4. Line 12. Use "... the largest corrections for Pb.".

Page 4:
 - Fig. 2. I cannot distinguish between your slightly different shades of red, blue, and green. I am also
   not a fan of the different colored horizontal bands of bin width that just add business and little content.
   Perhaps it is better to use different color symbols and symbol types for the z bins on each plot and use
   a gray scale for the bin widths. The detail about the different bin widths for each PT2 is not so important
   to reflect on the plot, so I would use a single light gray band for the PT2 bin width of each bin.
 - Fig. 2 caption.
   - Line 1. Use "... bins of $\nu$ (different columns) and $z$ ...".
   - Line 5. Use "... in the bin.".
 - Paragraph 1. Line 2. Use "... took place and were calculated ...".
 - Paragraph 1. Line 3. Use "... [35]. Calculation of the ...".
 - Paragraph 1. Line 5. Use "... [36]. Both corrections are incorporated ...".
 - Paragraph 1. Line 6. Use "Additionally, there were radiative ...".
 - Paragraph 1. Line 8. Use "... those were incorporated ...".
 - Paragraph 1. Line 9. Use "... and were accounted for ...".
 - Paragraph 1. Line 13. "-17\% to +8\% above unity". What do you mean by "above unity"? Is this term even
   necessary here?
 - Paragraph 1. Line 17. Use "... structure functions. These corrections affect ...".
 - Paragraph 1. Line 20. Use "... from both the leptonic and hadronic ...".
 - Paragraph 1. Line 23. Use "... (endcaps) of the liquid-deuterium target cell.".
 - Paragraph 1. Line 25. Use "liquid-deuterium".

Page 5:
 - Fig. 3. This figure is absolutely unreadable to me in its current form. There has got to be a better way
   to convey this information. The symbols on each postage stamp plot are utter unreadable and the text
   legend at the both is of such a small font size as to make one's eyes go cross. If your point is that
   the different points in each z bin for each target are similar, perhaps just show an average. If that is
   not acceptable, remove the statistic error bars as the box outline conveys this message. You have to do
   something to make this more digestible and less busy.
 - Paragraph 1. Line 12. "varies from -17\% to +8\% ... $(Q^2,\nu,z)$ binning." This just repeats the text
   word-for-word from the previous paragraph. Please review.
 - Paragraph 1. Line 14. Use "... of bins that have significant ...".
 - Paragraph 2. Line 16. Use "... and Pb, respectively, in the ...".
 - Paragraph 2. Line 21. Use "... shapes ranging on average ...".
 - Paragraph 2. Line 24. Use "... bin-by-bin uncertainties in $(Q^2,\nu,z)$, ...".
 - Paragraph 2. Line 27. Use "... and Pb, respectively.".
 - Paragraph 3. Line . Use "length-dependent".
 - Paragraph 4. Line 1. Use "Figure~2 shows ...". (no abbreviation starting a sentence)
 - Paragraph 4. Line 3. Use "... and, again, an overall decrease ...".
 - Question: As model calculations (especially GiBUU) should be available or can be done, this paper seems
   deficient with no theory comparisons. You have some hand-wavy discussions, but these are no so impressive
   without the calculations included here. I think this lack of theory detracts from this work.

Page 6:
 - Paragraph 2. Line 4. You need to add a reference to the mention of the previous published HERMES results.
 - Paragraph 3. Line 6. Use "... opposite to that measured for ...".
 - Paragraph 4. Line 7. Use "... behavior that leads to ...".
 - Paragraph 6. Line 4. Use "... hadron interactions, allowing for ...".
 - Paragraph 6. Line 13. Use "... searches for di-quark correlations ...".
 - Paragraph 6. Line 18. Use "... such as, clean measurements ...".
 - Paragraph 6. Line 20. Use "... nuclear medium and studies of ...".

References:
 - Do not include arXiv information for already published papers.
 - Include Collaboration names as "(HERMES Collaboration)" or "(CLAS Collaboration)", etc.
 - [31]. The list of names here is incomplete. Better to use "A. Airapetian {\it et al.}.
 - [32]. The Mecking paper is not a CLAS Collaboration paper.
 - [33]. Use "H. Hakobyan {\it et al.}".
 - [46]. Use "W.K. Brooks {\it et al.}".
 - [47]. Use "M. Barabanov {\it et al.}".