[Clascomment] OPT-IN:First Measurement of Deeply Virtual Compton Scattering on the Neutron with Detection of the Active Neutron

[Stepan Stepanyan]

- line 40, remove off, should be "or a meson on ..."
- In line 50, I suggest removing "in DVCS" at the end of the line. The parameterization is not solely for DVCS
- line 87, H1 and Zeus measured the DVCS cross section at HERA: F. D. Aaron et al. [H1 Collaboration], Phys. Lett. B 659 (2008) 796; A. Aktas et al. [H1 Collaboration], Eur. Phys. J. C 44, 1 (2005); C. Adloff et al. [H1 Collaboration], Phys. Lett. B 517 (2001) 47.
[2] S. Chekanov et al. [ZEUS Collaboration], JHEP 0905 (2009) 108; S. Chekanov et al. [ZEUS Collaboration], Phys. Lett. B 573, 46 (2003). 
The BSA was measured only by Hermes, but the sentence is not just asymmetries.
- line 88, "indications on $\tild H$," not sure what this means, maybe "limitations on $\tild H$"? 
- line121, "active" -> "recoil"?
- edline 127, the phrase "in dedicated Moller run", the "Moller run"  is really jargon, how about "using the Moller polarimeter" instead?
- line 128, no need for "cell" at the end of the sentence, 
- line 129, remove "," after "run" and "B"
- line 134, the sentence is incomplete, events are selected for something. Add "for the DVCS analysis" at the end.
- line 139, move the reference for HTCC, [34], out of brackets. Brackets are for ECAL only.
- line 143/144: Analysis question - we do not have seamless transition from FT to FD, so how you can have such perfect alignment for photon at 5 degrees. I believe real acceptance for FT is 4.5 and does not start at 2, it is more of 2.5 degrees. For ECal, any fiducial cut will bring you minimum angle at least to 6 degrees. Can you clarify this point. I also do not see how you detect electrons at 5 degrees.
- line 146 and 148, move the references to CND, [38], and CTOF, [38], out of brackets.
- line 180, there are much fewer false "photons" that are part of the electron shower than photons that have been radiated by the electron while passing through the target, scattering chamber, and the detector elements. The cut removes them too, just that the description of the photons is incomplete.
- line 186, it is better to say "from the reaction $ed\to ...".
- line 199, "the detected and the reconstructed photon", some of us may understand what this means, but for a nominal reader, this is a confusing statement. Add at least the reaction for missing angle calculation. You have a couple of definitions of X above this line and should clarify which one is this.
- line 200, reference to Figure 2. Fig.2 top graph, the MM of ed->en\gammaX, this variable is not in your exclusivity variable list. Instead, you have two other MMs that have not been presented. 
- line 211, which exclusivity variable was used? You leave the reader in suspense; you should quote the exclusivity variable used for BDT.
- line 217, the pi0 contamination. The paragraph says it was subtracted for each kinematic ben. Was the subtraction done for each helicity state separately? If yes, you should add the statement; otherwise, your asymmetry will be incorrect as pi0 will have asymmetry.
- line 250, again, the phrase "Moller run" is not good, how about "measurements with the Moller polarimeter."
- line 261, if you have space, it would be useful to write the formula of the function used in the fits in Fig.4 (the blue line). was it a+b*sin(\phi)? or just b*sin(\phi)?  
- Related to Figure 6, this is an important study, but without knowing the separation when these data are not included, it does not have the desired value. Also, citation [48] does not have the extraction of CFF for d and u separated.