[Clascomment] OPT-IN: Beam Spin Asymmetries in Semi-Inclusive pi0 production

[Daniel Carman]

					Apr. 29, 2011


Dear Mher et al.,

I have read through your pi0 BSA paper and pass along my comments
to you below. As I am not all that familiar with the physics in
this work, I will leave it to others who are more knowledgeable to
comment on that. Let me know if you have any questions.


			   Regards,

				  Daniel

********************************************************************
General.
  - You have not been consistent with usage of "single spin asymmetries"
    or "single-spin asymmetries". Pick one form and be consistent
    through the paper.

Page 1.
 - Line 1. Use "In recent years it has become clear that ...".
 - Line 11. Use "... partons and the first unambiguous ...".
 - Line 15. Use "TMDs were first suggested to explain ...".
 - Line 18. Here you use "transverse momentum dependent distributions"
            as opposed to "Transverse Momentum Dependent distributions"
            or TMDs. Is there a reason for this? Are you speaking about
            some general as opposed to TMDs themselves?

Page 2.
 - Line 48. Use "... of TMDs also strongly depends on the ...".
 - Eq. 2 Here you use bold face notation for vectors, but in lines
   76 to 80 you use roman font for vectors. Be consistent in your
   notation.
 - Line 89. Use "capital letters".

Page 3.
 - Line 136. Use "beam SSA".
 - Line 154. Use "calorimeters".
 - Line 176. Use "... for the pi0 transverse ...".

Page 4.
 - In your form of Eq. 3, you do not mention explicitly corrections
   for beam charge asymmetries of helicity-dependent dead times. Seems
   this is worth mentioning.
 - Add a comma after Eq.3.
 - Line 207. Use "... selecting the pi0 from the ...".
 - Line 223. Use "... within the available statistics ...".

Page 5. 
 - Line 240. Use "Refs.[12,49]".
 - Line 255. Use "... 6 GeV, the ...".
 - Fig. 4. The hatching about ALU=0 is very hard to see. It needs to
   be made darker with thicker line types.