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

[Luciano Pappalardo]

The paper is very well written and a pleasure to read. The results are very interesting and well presented. I have only a few minor comments:

119-120: "Sizeable beam SSAs were predicted for pion production". Does this apply also for neutral pions? Apparently it has been tested on positive pions only.

150: "detected in CLAS" -> "detected by the CLAS spectrometer"

Figure2: try to move this figure on pag. 4, where it is referred to.

Figure3: - The axis labels and the internal labels (bins in x) are too small, also compared to those of the other figures in the paper. Try to use the same format as for the other figures. 
- In second line of the caption use "arising" instead of "arises". 
- Why not showing also the complementary plot, with A_LU vs. x in bins of P_T? The two plots together would provide the complete picture.

188: "integral of the histogram" -> "integral of the 2-gamma invariant mass peak"

200-203: what about the contributions from acceptance and smearing effects? They might be small compared to the other contributions, but at least mention them.

225-227: Since the pi0 are the main results of this paper, you should refer HERE to figure 4 (rather than in line 231).  Then in the next paragraph you can say that the same figure also shows the pi+ results for comparison.  

Figure 4. : the left part of the plot is too crowded. I propose to move the pi+ labes besides, rather than below, the pi0 ones.