[Clascomment] OPT-IN: Hard Two-body Photodisintegration of 3He

[Daniel Carman]

					     October 12, 2012


Dear Yordanka,

I have read through your draft paper on two-body photodisintegration of 3He. 
I include my comments and questions below. My general impression is that this
paper is reasonably well written, but I have my doubts that it can be published
in PRL if that is your plan. The paper as written is a bit too jargon-filled.
However, I will support whatever decision you and the other lead-authors make.
The paper is definitely worth submitting for publication. Let me know if you 
have any questions.

Note: My comments are based on the printed line numbers in the draft.


			   Regards,

				  Daniel

********************************************************************
Page 1.
 - Abstract. Line 6. Use "... dimensional scaling in the photodisintegration of ...".
 - Line 2. Use "... that carry a finite fraction of the particle ...".
 - Line 11. Use "Currently, there is strong experimental ...".
 - Line 16. Use "... years of effort, is not ...".
 - Line 27. The second paragraph of the paper goes without a break for a full page.
     You need to come up for a breath. I suggest to start a new paragraph beginning
     with the sentence "The controversy of the meaning of ...".

Page 2.
 - Line 31. Use "... modeling it, which vary from process ...".
 - Line 35. Use "... factorization [3-5] have been developed ...".
 - Line 42. To improve the readability here, I would begin a new paragraph with the
     sentence "Fundamentally, the origin of ...".
 - Table I. In table heading, use "$s$" and "$n$".
 - Line 63. I suggest you begin a new paragraph with the sentence "For reactions that
     are dominated ...".

Page 3.
 - Line 105. Use "... size of the target ...".
 - Line 124. I think it improves the structure when you do not say "the CLAS". There are
     quite a few instances of this usage in this paragraph and later in the paper that I
     would fix. Just say "CLAS". For example here, use "... used CLAS to measure ...".
 - Line 134. There are 57 scintillators in each CLAS TOF sector, not 48.
 - Line 137. Use "... the target, were used to measure ...".
 - Line 140. Use "... 360$^\circ$, excluding the angles ...".
 - Line 175. Use "... correction, which is at the ...".
 - Line 177. Use "... E93-044, only events with exactly two positively charged tracks were
     considered.".
 - Line 196. To improve readability, begin a new paragraph with the sentence "Figure 2 
     demonstrates the ...".
 - Line 198. Use "... at a proton c.m. angle of ...".
 - Line 204. Use "... due to the remaining background ...".

Page 4.
 - Fig. 2 caption. 
    - Line 4. Use "Events from the $pd$ final state ...".
 - Line 207. I suggest "Background subtracted yields were corrected for the inefficiency
      of the procedure that selected the photon ...".
 - Line 210. I have no idea where this factor of 1.0338 comes from.
 - Line 210. Begin a new paragraph with the sentence "The CLAS acceptance for the reaction ...".
 - Line 215. Use "analyzed".
 - Line 218. Use "... real data were determined ...".
 - Line 219. Use "... at a c.m. angle of ...".
 - Line 221. Here I believe you are talking about a systematic uncertainty assignment but the
      text is unclear.
 - Line 223. Use "$s$ > 10~GeV$^2$".
 - Line 243. For clarity, use "... smoothly to $E_\gamma$=0.7~GeV ...".

Page 6.
  - Line 416. Use "systematic uncertainty".