[Clascomment] OPT-IN:First measurement of hard exclusive pi-Delta++ electroproduction beam-spin asymmetries off the proton

[Daniel Carman]

Stefan,

As I have already reviewed a previous version of this manuscript for you, I do not have so
much more to pass along based on this most recent draft of your paper on the sigLT'/sig0
analysis of CLAS12 RG-A data for the pi-Delta++ final state. However, I pass along below my
remaining comments. You will note that I really do not have any remarks on the physics.
Anyway, if you have any questions, let me know.

Regards,
Daniel

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General:
 - When you write the percent symbol (%), you tend to put a space between the value and the %
   symbol. This should be removed. Use (for example), "86.6\%". Please update throughout the paper.
 - You reference supplementary material that will be submitted with the paper. This should be
   made available as part of this review to make sure that it is correct, the presentation is
   clear, and that the english/grammar are reviewed.
   
Page 1:
 - Line 12. Use "... enable us to access the three-dimensional (3D) structure of the nucleon ...".
 - Line 19. Use "... large invariant energy $W$, ...". Also you have not defined $x_B$ and should
   do so as it is a key variable in this work.
 - Line 21. Use "factorization".
 - Line 28. Use "... transition GPDs, have been introduced.".
 - Line 70. Use "... for the $p \to Delta$ deeply virtual Compton scattering (DVCS) process.".
 - Line 74. Use "... e'N^*\gamma)$, but also based ... [17,18], suffered from ...".
 - Line 77. Use "... nucleon resonances, as well as from ...".

Page 2:
 - Fig. 1. The variable labels should use a larger font size.
 - Line 83. Keep units with their values and not separated across line breaks using, e.g.
   "1.6~GeV".
 - Line 107. Use "Jefferson Laboratory (JLab)".
 - Line 130. Use "... forward kinematics were selected ...".
 - Line 138. Use "... $\rho$ production was reduced by ...".
 - Line 143. Use "... background that dominates below ...".
 - Line 156. Use "Geant4-based".

Page 3:
 - Line 203. Use "... contributions were separated ...".
 - Line 204. Use "... asymmetry was calculated based ...".
 - Line 210. Use "... (see Fig. 5). A fit of the data with a $\sin \phi$ function was then
   applied.".
 - Fig. 5. Figure quality seems poor (grainy). Also the axis labels/values need to have a larger
   font size.

Page 4:
 - Line 220. Use "... to be on the order ...".
 - Line 225. Use "... found to be on the order ...".
 - Line 226. Use "... 2.8\%, which was treated as part ...".
 - Line 231. Use "... a Geant-4 based MC ...".
 - Line 236. Use "... to be of the same order.".
 - Line 238. Use "... to be on the order ...".
 - Line 243. Use "... each bin was defined as the ...".
 - Line 252. Use "... from Refs.~[32,33], which can be ...".
 - Line 255. Use "... shows a shape that can be explained ...".
 - Line 292. Use "... $\pi^+$ even though there is no ...".
 - Line 316. Use "... GPD-based predictions ...".
 - Line 328. Typo on "helicity".

Page 5:
 - Fig. 6 caption:
   - Line 3. Use "... on top of each sub-figure."
 - Line 377. Use "... $N \to N^*$ deeply virtual meson production (DVMP) channels ...".

References:
 - [23]. Do not include doi link for this published paper. You do not do this for any other.
 - [25],[26],[27]. "et al." should be italics font.