OPT-IN: Exclusive Ï0p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV2 ⤠Q2 ⤠1 GeV2

[Daniel Carman]

Dear Nick et al.,

I have read through the draft of your pi0-p electroproduction paper include my comments
below. Most of what I have provided below will serve to improve the grammar and readability
of the paper. If you have any questions, let me know.

Regards,
Daniel
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General:
 - Use "(Color online)" in all figure captions for which you have a figure that uses color. You have
   done this for some, but not all, figures.
 - You have a typesetting issue where units are sometimes separated from their corresponding
   values across lines. To avoid this in latex use, e.g., "2.5~GeV".
 - You are not consistent in your notation with cos theta. Sometimes you use "$\cos\theta$" and
   sometimes you use "$\cos \theta$". Choose one and use it throughout for your cosine notation.
 - Put the figures in the order in which they are cited in the text. Things get a bit random starting
   with Fig. 21.

Page 1:
 - Abstract:
   - Line 4. Use "center-of-mass".
   - Line 7. Use "high-lying".
   - Line 9. Use "... both single- and double-pion electroproduction, ...".
 - Right column:
   - Line 55. Should not begin a new paragraph.
   - Line 63. Use "model-independent".
   - Line 78. Use "... framework of the continuum QCD Dyson-Schwinger Equation (DSE) approach ...".

Page 2:
 - Left column:
   - Line 96. Use "... for the generation ...".
   - Line 106. Use "momentum-dependent".
   - Line 127. Use "... that are chiral parity partners ...".
 - Right column:
   - Line 165. Use "... resonance electrocouplings.".
   - Line 166. Use "... electroproduction channel offers preferential ... for the exploration of ...".
   - Line 177. Use "Recently, new CLAS ...".
   - Line 192. Use "... for both electrons ($e$) and protons ($p$) ...".

Page 3:
 - Left column:
   - Line 193. Use "Event selection was completed ...".
   - Line 196. Use "... bin centering were developed ...".
   - Line 198. Use "... normalization was checked against ...".
   - Line 199. Use "... systematic uncertainties were identified.".
   - Line 201. Use "... $W$ regions and estimates are provided of the resonance contribution into the
       cross section. The extracted Legendre polynomial moments show the sensitivity ...".
 - Right column:
   - Fig. 1. Poor quality figure. Hard to read labels for pi0, theta, phi.
   
Page 4:
 - Left column:
   - Line 260. Use "... [47] were used for ...".
   - Line 290. Use "The EC were used to ...".
 - Right column:
   - Line 291. Use "minimum-ionizing".
   - Line 294. Use "For particles that hit the calorimeter ...".
   - Fig. 2 and Fig. 3 captions. Use "... axis represents the number of events.".

Page 5:
 - Fig. 4 and Fig. 5 captions. Use "... axis represents the number of events.".
 - Right column:
   - Line 371. Use "The actual average beam position was ...".

Page 6:
 - Left column:
   - Line 385. Use "Instead, we reconstructed the four-vector ...".
 - Right column:
   - Fig. 8 caption. Use "... axis represents the number of events.".
   - Line 420. Use "... for reliable $\pi^0$ separation.".
   - Line 422. Use "... was necessary in order to limit ...".
   - Line 424. Use "... cut was accounted for in ...".
   - Line 426. Use "... finalized our exclusive event selection.".
   - Line 440. Use "... (see Fig. 9 and Table I) ...".

Page 7:
 - Left column:
   - Line 442. Use "... (see Fig. 10 and Table II) ...".
 - Right column:
   - Line 464. Use "... to monitor the Faraday Cup performance and ...".
   - Line 476. Use "These windows were made of 15~$\mu$m aluminum foil.".
   - Line 480. Use "... same particle identification procedure ...".
   - Line 481. Use "... identification, was applied to the ...".

Page 8:
 - Left column:
  - Line 494. We did not have surveyed magnetic field for the torus in CLAS and relied only
     on FEA calculations from OPERA/TOSCA.
 - Right column:
   - Line 540. Use "... section might not vary ...".
   - Line 544. Use "... evaluate the corrections. We divided each bin over ...".

Page 9:
 - Right column:
   - Table III caption. Use "... the systematic uncertainties.".

Page 10:
 - Left column:
  - Fig. 15 caption. Use "\cos"
 - Right column:
  - Line 582. Use "... proton identification, tracking ...".
  
Page 11:
 - Left column:
   - Line 608. Use mC for units, not C.
   - Line 615. E_TOF is not explained anywhere in the paper as is indicated. This definitely needs
       to be addressed somewhere.
 - Right column:
   - Line 670. Use "electrocouplings".

Page 12:
 - Fig. 17 caption:
   - Line 3. Use "The systematic uncertainties are shown by the shadowed areas at the bottom of the plots.".
 - Fig. 18 caption:
   - Add "The systematic uncertainties are shown by the shadowed areas at the bottom of the plots.".

Page 13:
 - Left column:
   - After line 717. Another paragraph is needed here to add some degree of interpretation of what the
     Legendre moments indicate. Also, why did you choose to show only C1 and A0 and none of the B terms?
 - Right column:
   - Line 738. Use "... sections as a function of ...".

Page 14:
 - Fig. 19 caption. Use "The shaded bands represent the systematic uncertainties.". This comment is also
   applicable for Figs. 20, 21, 22, 23, 24, and 25.
 - Left column:
   - Line 765. Use "... final state due to isospin ...".
 - Right column:
   - Line 785. Use "model-independent".
   - Line 792. Use "This was shown in the ...".

Page 15:
 - Left column:
  - Line 805. Use "... when the $A_{1/2} ...".
  - Line 818. Use "... + \epsilon \sigma_L$ (Fig. 23) ...".
  - Line 824. Use "... the combined studies of all exclusive structure functions are of particular ...".
 - Right column:
  - Line 851. Use "... data with the JLab/YerPhi model ...".
  - Line 860. Use "... decays of isospin 3/2 ...".

References:
 - [12] overlaps the next column.
 - [19]. Use "M. Ungaro {\it et al.} ...".
 - [40] Use "K. Park {\it et al.} ..."
 - [57] Use "V. I. Mokeev and I. G. Aznauryan, ...".

Page 18:
 - Fig. 21 caption. Use "... model expectations with the $\Delta(1620)1/2^-$ resonance turned on/off: ...".
 - Fig. 22 caption. Use "... Legendre moment at different photon virtualities $Q^2$ as a function of ...".

Page 19:
  - Fig. 24 caption. Use "... Legendre moment at different photon virtualities ...".

Page 20:
 - Fig. 25 caption. Use "$\sigma_{TT}$ unpolarized structure function at ...".