OPT-IN:Beam Spin Asymmetry Measurements of Deeply Virtual π0 Production with CLAS12

[Daniel Carman]

Andrey,

I have read through your paper draft on the sigLT'/sig0 analysis of CLAS12 RG-A data for the
pi0 DVMP kinematics and pass along my comments below. If you have any questions, let me know.

Regards,
Daniel
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Page 1:
 - Line 9. Use "... with longitudinally polarized ...".
 - Line 9. Use "liquid-hydrogen".
 - Line 15. Use "... were compared to a theoretical model ... Regge formalism that was extended ...".
 - Line 25. Use "... shown in Fig. 1 ...".
 - Line 45. Use "... (... $E$, and $\tilde{E}$), ...".
 - Line 47. Use "... skewness $\xi$, and the four-momentum ...".
 - Line 53. Use "cannot".
 - Line 54. Use "... from the chiral-even sector.".

Page 2:
 - Line 70. Use "... $x_B$, and ...". Also, you never define the kinematic variable $x_B$.
 - Line 79. Use "... beam spin asymmetry (BSA) is defined ...".
 - Line 84. Use "... $\sigma_{TT}$, and the polarized ...".
 - Line 118. Use "... and momentum conservation can be used ...".
 - Line 122. Use "... production) and from reactions ...".
 - Line 129. Use "... angles of the reconstructed ...".
 - Line 131. End this bullet with a semi-colon (not a period).
 - Line 134. End this bullet with a period (not a semi-colon).
 - Line 138. Use "Figure 2 illustrates the ...".
 - Line 139. Use "... $\Delta P_z$, and $\Delta \phi_{X\pi}$ cuts ...".
 - Line 140. Use "... squared of the $epX$ system ...".
 - Fig. 2 caption.
   - Line 1. Use "... squared of the $epX$ system ...".
   - Line 2. Use "... application of the exclusivity constraints. The ...".
   - Line 3. Use "... cuts on $MM_{epX}^2$ that were also ...".
 - Line 143. Use "... all exclusivity cuts, ...".
 - Line 148. Use "... shown in Fig. 3. As a cross-check, the ...".
 - Line 152. Use "... from the sideband subtraction method, ...".

Page 3:
 - Fig. 3 caption.
   - Line 4. Use "The black solid histogram ...".
   - Line 5. Use "... helicity and the read dashed histogram corresponds ...".
   - Line 7. Use "... $3\sigma$ cuts on the invariant mass ...".
 - Line 163. Use "... $-t$, and $\phi$ and ...".
 - Line 171. Do not begin a new paragraph with this sentence. Include in the previous paragraph.
 - Line 172. Use "... to extract the BSA.".
 - Line 175. Use "... the BSA was plotted as a function ...".
 - Line 176. Use "Figure 5 shows the BSA as a function ...".
 - Line 179. Use "... by Eq. (1). The ...".
 - Line 181. Use "... parameterizations of the unpolarized ...".
 - Line 182. Use "... terms in Eq. (1) on ...".
 - Line 184. Use "... for the unpolarized structure ...".
 - Line 187. Use "The extraction of the BSAs for ...".
 - Line 210. Use "... from Eq. (1) on the ...".
 - Line 212. Use "were combined in quadrature ...".
 - Line 214. If I added your quoted systematic uncertainties in quadrature, I get 0.021, not 0.015. Please
   check.
 - Line 215. What haven't you separated your systematic uncertainties into point-by-point and scale type?
 - Line 216. Use "... for the BSA moments ...".

Page 4:
 - Fig. 5 caption.
   - Line 2. Use "... for two representative kinematic bins.".
 - Line 218. Use "... x_B}$ bins ...".
 - Line 227. Use "... interplay between the ...".
 - Line 269. Use "... on Eq. (3) the ...".
 - Line 275. Use "... substantially larger BSA values, ...".
 - Line 281. Use "... lower $Q^2$ bins, while the increase ...".
 - Line 291. Use "... of $\bar{E}_T$, such as ...".
 - Line 293. Use "... COMPASS [21], and observables ...".

Page 5:
 - Fig. 6 caption.
   - Line 4. Use "... predictions from the Regge-based ...".
 - Line 300. Use "... precision $\pi^0$ BSA data from ...".
 - Line 310. Use "... of the BSA measurements for ...".
 - Line 311. Use "$\vec{e}p \to e'p'\pi^0$".
 - Line 331. Use "... (DFG), and the Chilean ...".

References:
 - Include the Collaboration names with the papers, especially for "CLAS Collaboration" papers.
 - You do not use a consistent journal abbreviation scheme. All are abbreviated except for "Physics
   Letters B".
 - [5]. No spaces between the journal name. Use "Eur. Phys. J".