[Clascomment] OPT-IN: Measurement of the Q2 1 -dependence of the deuteron spin structure function g1 and its moments at 0.02 < Q2 < 0.7 GeV2 with CLAS

[Daniel Carman]

Dear Alexandre et al:

I have read through your draft paper on the g1 structure function that
is now undergoing CLAS ad hoc review. I include my comments below. I
am not a particular expert on the physics results reported, but I was
able to follow the paper and it seems reasonably clear to me. If you 
have any questions on my comments below, let me know.

Regards,
Daniel

-----------------------------------------------------------------------------
Page 1:
 - Abstract. Line 4. Use "polarizability".
 - Line 17. I suggest "The reasons being that nucleon structure ...".
 - Line 18. Use "Quantum Chromodynamics".
 - Line 43. The sentence "This article reports" should begin a new
   paragraph.
 - Line 44. Use "... to this latter topic ...".
 - Line 47. Use "polarizability".
 - Line 48. Use "transferred".
 - Line 54. Use "... measurements were dedicated, however, to ...".
 - Line 65. Use "transversely polarized".
 - Line 67. Use "... from measurements on ...".
 - Line 69. Use "... effects in the deuteron ...".
 - Line 70. Use "... for $^3$He, but to obtain ...".

Page 2:
 - Line 5 after line 77. Use "The latter was originally ...".
 - Line 85. Use "..., that are quite ...".
 - Line 98. Use "$^3$He".
 - First line after Eq.(2). Use "Compton".
 - Second line after Eq.(2). Use "... $\Gamma_v$ is the ...".
 - Line 113. Use "... generalizations in Eqs.(2) and (3) ...".
 - Line 134. Use "... allowing measurement of the whole sum rule
   integrand, which is at variance with photoproduction that requires
   ... more associated systematic uncertainties.".

Page 3:
 - Line 155. The sentence "The data for ... calculations." is quite
   awkward as written.  I take issue with the phrase "typically agree"
   and with "one type of XPT calculation". These phrases are vague and
   do not make it clear what you are talking about.
 - Line 160. Use "... and calculations limited ...".
 - Line 179. Use "... moved 1~m upstream of the nominal CLAS center ..."
 - Line 183. The value of Q2 = 0.84 GeV2 disagrees with the Q2 range in
   the title of the paper.
 - Line 184. Include units on the nucleon mass.
 - Line 209. Use "... and M{\o}ller-derived polarizations ...".
 - Line 217. Use "Besides the new CC used for data acquisition triggering
   and electron identification, CLAS was comprised of three multi-layer
   drift chambers ... particles, and time-of-flight counters and 
   electromagnetic calorimeters (EC) for further particle identification.
 - Line 224. Use "... with an EC-only ...".
 - Line 226 should not begin a new paragraph.
 - Line 227. End this sentence with a period.
 - Line 232. Use "... and target polarizations:".
 - Eq.(5) should end with a comma for proper punctuation.
 - Line 239. Use "... is the CLAS detector acceptance, which also ...".
 - Line 244. Use "... $\theta$ the polar scattering angle.".
 - Line 245. Use "... $\Delta \sigma$, which is ...".

Page 4:
 - Line 254. Use "... scattering from deuterium ...".
 - Line 256. Use "Eq.(7)".
 - Line 257. Use "Geant-3".
 - Line 259. What do you mean by "smearing effects"?
 - Line 260. GPP does not account for detector resolutions. The nominal
   detector resolutions are included in the simulation. GPP provides
   a mechanism for additional resolution smearing to account for mismatches
   between the simulation and the data due to various effects that are not
   fully accounted for in the simulation.
 - Line 263. Use "Eq.(5)".
 - Line 272. The quantities F2, R, and A2 are not defined.
 - Line 279. Use "... polarized yield differences ...".
 - Line 286 should not begin a new paragraph.
 - Line 291. Use "... acceptance and high detector ...".
 - Line 319. This largest Q2 bin disagrees with the Q2 range in the title.

Page 5:
 - Fig. 2 caption:
   - Line 6. Use "... from the CLAS EG1b ...".
   - Line 6. Add references in the caption to the EG1B and E143 data.
   - Line 7. Use "... show various models and $\chi$PT calculations as
     described in the text.".
 - Line 328. Use "... minimum $Q^2$ ...".
 - Line 334. Use "... calculations from Lensky ...".
 - Line 339. Use "... [25] agree with the data ...".
 - Line 341. Use "... [24], which agree with ...".
 - Line 342. Use "... high $Q^2$, continue ...".
 - Line 350. Use "... resonance contributions.".
 - Line 354. Use "... contribution).".
 - Line 355. Use "... because the CLAS resolution ...".
 - Line 357. Use "... integration. The same ...".
 - Fig. 3 caption. Line 2. Use "Fig. 2".
 - Line 367. Include reference for Lensky.
 - Line 368. Use "This 10\% away from the prediction of Ref.[34], which
   represents ...".
 - Line 381. Use "... Eq.(4), and is shown in Fig. 4.".

Page 6:
 - Fig. 4 caption. Add "See Fig. 2 for legends and theoretical
   calculations.".
 - Line 394. Use "polarizability".
 - Line 406. Use "... with the GDH ... summed over the proton ...".
 - Line 414. Use "... benchmark polarization observables ...".

References:
 - The references need to be tidied up a bit.
 - Each reference should end with a period. Many end with no
   punctuation or a comma or a semi-colon.
 - Ref.[1]. Do not include the doi reference.
 - Ref.[4]. Do not include the title
 - Ref.[18]. Include semi-colon after first reference.
 - Ref.[29] is not a CLAS Collaboration paper.