[Clascomment] OPT-IN: Measurement of charged pion production in deep-inelastic scattering off nuclei with the CLAS detector23

[Daniel Carman]

Dear Sebastian,

I have read through the draft of your paper on the charged pion multiplicity ratios
that is intended for publication in Phys. Rev. C. I do not have substantive comments
on the physics. However, I do have some comments on grammar/style to try to improve
the presentation a bit. If you have any questions, let me know.

Regards,
Daniel
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General:
- You are not consistent with hyphen usage: e.g. "charged-pion" vs. "charged pion",
"cross-section" vs. "cross section", "drift-chamber" vs. "drift chamber". Please review
the manuscript.
- You have some verb tense issues where you use present tense when you should use past
tense. I will point these issues out in my comments below.

Page 1:
 - Line 38. Use "In the DIS regime ...". (You already introduced the acronym in the sentence
   on line 27.
 - Line 37. Use "... propagates through the nucleus."
 - Line 66. Use "... and deuterium (*D) corrected for detector acceptance:".
 - Line 67. I would add something like "Here $\nu = E_e - E_{e'}$ is the energy transfer ..."
   to be clear what energy transfer you are referring to.

Page 2:
 - Line 90. Use "... and a hadronic phase ...".
 - Line 108. Use "... (JLab) Hall~B held unique ...".
 - Line 114. Use "... detector was suited to study ...".
 - Line 117. Use "... capabilities enabled studies ...".
 - Line 131. I suggest "... \to e' + \pi^{\pm} + X$, ...".
 - Lines 151 and l52. Include a space before the "$\times$" symbol.
 - Line 156. Use ".. which provided a field ...".
 - Line 161. I suggest "... and a sampling electromagnetic calorimeter ..." to give context for
   your later discussion of sampling fraction.
 - Footnote 1. Use "$z$-axis".

Page 3:
 - Line 180. Use "... CC, and EC.".
 - Line 191. Use "... measurements was applied ...".
 - Line 197. Use "... which were inconsistent ...".
 - Line 199. Use "... resolution ranged ...".
 - Footnote 2. I recommend "The EC effective ...".
 - Footnote 2. Use "... sampling fractions were within ...".
 - Line 221/222. Here you use the symbol "E" to be beam energy, when you used it on line 80 with
   a different meaning. I suggest that you use "$E_e$" (as I noted in my comment for line 67).
 - Line 234. I prefer "beamline".
 - Line 242. Use "... vertices differed by less ...".

Page 4:
 - Line 255. Include a reference to PHYTHIA here.
 - Line 259. Use "... package [21], which ...".
 - Line 265. Use "... combined effects that account for particle tracking and identification, ...".
 - Line 274. Use "The data were corrected ...".
 - Line 286. "The acceptance correction on the ratio of the inclusive electron yields ...". Please
   clarify what this means. Are you referring to the ratio of electron yields from deuterium to any
   of your nuclear targets?
 - Line 292. Use "... corrections were applied on a bin-by-bin basis ...".
 - Line 305. Use "... for Fe, and ...".
 - Line 307. Use "... corrections were calculated ...".
 - Line 310. Use "... cross sections were calculated using the prescription of ...".
 - Line 311. Use "... Ref. [28].".
 - Line 313. Use "... for Fe, and between ...".
 - Line 319. Use "... $z$, and ...".
 - Line 323. Use "... yield were estimated.".
 - Line 324. Use "... so no correction was applied ...".
 - Line 325. Use "... uncertainty was assigned instead.".
 - Line 331. Use "... uncertainty on the kinematics for each ...".

Page 5:
 - Line 345. Use "... ranged from ...".
 - Line 352/353. Here use use "$\Delta Z"$ with a capital Z, however, you first introduced us to the
   $z$-axis to mean the beamline with a lowercase z. So this amounts to a notation change. However,
   you should also be careful as you also use "z" for your energy fraction variable.
 - Line 400. Use "... $z$, and ...".
 - Line 403. Use "... to the virtual photon axis: ...".
 - Line 407. Use "... repeated the analysis varying the ...".
 - Line 426. Add a reference for GIBUU the first time you mention it.
 - Line 429. Use "... the high $K^+$ rejection ...".
 - Line 432. Use "... particle identification at ...".
 - Line 435. Use "... assigned for the $\pi^+$ ...".
 - Line 437. Use "... uncertainty was assigned ...".
 - Line 440. Use "... momentum was above ...".

Page 6:
 - Line 446. Use "... the results varied ...".
 - Line 449. Use "... assigned for the $\pi^+$ ...".
 - Line 453. Use "... variation was negligible ...".
 - Section on "Coulomb and radiative effects" vs. section on "SIDIS radiative effects". I must admit I
   am not sure what the distinction is between these two contributions. You have radiative effects on
   the beam electron and scattered election. You have additional effects if you detector particles in
   the final state because their detection changes the phase space for the electron. Is this what you
   are getting at here? If so I suggest you add some clarification because I did not know exactly what
   you were talking about and it made me worry that you were double counting in your considerations.
 - Line 494. Use "In addition, ...".
 - Line 499. Spurious "due to".
 - Line 505. Use "... radiative correction treatments, ...".
 - Line 526. Use "Eq. 1".

Page 7:
 - Line 555. Use "... 4.25~GeV, 1.0 ... 4.0~GeV$^2$, and ...".
 - Line 562. This list of minimum values for $R_h$ is a bit misleading. They simply represent the
   minimum values of $R_h$ in your specific kinematic acceptance at a specific value of z to allow
   comparison from target to target. Your presentation seems to be presenting them as something
   more than this. Please review the text here.
 - Line 588. Use "(nFFs)".
 - Line 592. You have introduced the acronym "DSS" without definition or context.
 - Line 592. Use "... as a baseline.".

Page 8:
 - Table I. Remove the period from "norm." and "negligible." for a cleaner notation.
 - Figure 1 key. You use "Guiot et al.". This is awkward because this is only a two author paper. Better
   to use "Guiot/Kopeliovich" in your key or introduce a "GK" notation.
 - Figure 1 caption. Use "... and Pb targets, respectively.".
 - Lines 623-626 amount to an orphan paragraph. What model are you referring to here?
 - Line 628. Use "... and $\pi^-$, respectively.".
 - Line 634. Use "... the ratios over the wider ...".

Page 9:
 - Figures 2/3.
   - Use "... as a function of $z$ for various ...".
   - Use "... of $\nu$ (in different rows) ...".
   - Use "... Fe, and Pb, respectively.".
 - Line 642. Use "... experiment with the CLAS12 detector will ...".
 - Line 642. Include a reference to the CLAS12 detector - use the Burkert et al. NIM paper.
 - Line 647. Use "... hadrons due to final-state ...".
 - Line 649. Use "... and 5 show the multiplicity ...".
 - Line 665. Use "... model, $R_h > 1.0$ arises ...".
 - Line 666. Use "... interactions that may modify ...".

Page 11:
 - Line 731. You mention future experiments with CLAS12. You should reference the experiment numbers,
   with titles and spokespersons.
 - Line 735. Use "The combination of the present results from CLAS, and the future experiments from
   CLAS12 and the Electron-Ion Collider [42], will provide ...".
 - Line 735. What about the EicC? (There is more than one "electron-ion collider" to discuss now.)
 - Line 737. Use "... that will help to reveal ...".
 - Acknowledgments: Be sure to include the standard CLAS acknowledgment with the JLab DOE contract
   number.

Refs.:
 - Your references do not follow the accepted APS style and your chosen style varies quite a bit
   throughout your bibliography. This needs some cleanup.
 - Use "{\it et al.},".
 - Ref.[2]. What is this reference? A book or something else?
 - Sometimes you spell out the full journal name and something you use abbreviations.
 - Please include collaboration names in your references, e.g. "(CLAS Collaboration)".
 - Ref. [23]. Include a URL to this note.
 - Ref. [28]. Add spaces between the authors first initial and their last name.