OPT-IN: Target and Beam-Target Spin Asymmetries in exclusive Ï+ and Ïâ electroproduction with 1.6 to 5.7 GeV electrons

[Michel Garçon]

Dear Peter et al.

Here are a few comments on this paper which reads very well.

- consider adding "off the nucleon" in the title.
- line 20: I would not call "preliminary" an investigation dated  2003 and not published. What about "early" ?
- line 34: "independent" rather than "orthogonal". Also you say that epsilon is the fifth variable, but all results are plotted in bins of E. Also in the definition of binning on pages 13 and 14, there is no mention of binning in epsilon. There is some inconsistency here. I would not define epsilon as the fifth variable at the beginning.
- last equation page 3: nu is not defned.
- line 42: reduced usually refers to cross section divided by virtual photon flux factor, which you do not mention here. Still, only after this division do the quantities defined depend only on the 3 variables mentioned line 43.
- Table I: clearer to write 0.917 lA, and 0.145(L-lA). In the caption it is g/cm2, not gm.
- l 67: specify over which transverse size is the beam rastered.
- l. 85: the whole sentence "The distance...entire run" may be moved higher up.
- l. 88: 3/4, not 2/3.
- l. 93: it is either "positive target polarization" or "positive solenoid polarity"
- Table II or text around line 90: explain the notation i/o, and thus the terminology inbending/outbending, which are not defined the first time they are used l. 340.
- l. 133: 67& ?
- l. 195: minus sign missing in front of 0.11
- l. 196 and following: what about adding a missing energy plot ?
- Fig. 4: might be slmightly better to plot the two lower plot with delta_theta ranges of +-5 and +-7 degrees respectively.
- l. 242: I woudl repeat "count-weighted average". Also give reference to the CLAS data base.
-l. 259: closing paranthesis missing.
-l. 349: should explain why the 8 energies in Table 2 become 4 here.
- l. 417: "cut" -> "discarded".
- l. 427: might want to rephrase this for a publication.
-l. 443: Q2

Otherwise, should maybe discuss in the systematic errors the possible differences between quasi-free e(n) and free en. And I would purposedly write e(n) -> ep pi- evrywhere, or at least in the conclusion again.

Good work! 
Michel Garcon