[Clascomment] OPT-IN:Longitudinal target-spin asymmetries for deeply virtual Compton scattering

[Stepan Stepanyan]

Dear Silvia et al.,

abstract - phrase "..., which are a signature of the interference of the deeply virtual Compton
scattering and the Bethe-Heitler processes, ..." strictly speaking this is not true, in DVCS amplitude there is a term
$s^{DVCS}_{1,LP}$ that can generate sin(\phi) modulation.
line 27 - remove "and" after coma, nucleons are hadrons
line 31 - it use to be called Deep Inelastic Scattering (DIS), not deeply inelastic scattering
line 38 - sentence make no sense, should be revised. What it means "... considering only quark GPDs ..., there are four different GPDs ...
line 49 - if word "small" is used, then it should be "-t" not "t"
line 59 - better to say "The definitions of the kinematic variables are in ..."
line 67 - why BH is more important, what means more important, more important for what? Looks like improper use of word, instead of "important" may be better to say "larger" or "significant"
line 115 - I do not see where parentheses were open to close it after "...[11])", ")" must be removed.
line 124 - GPDs do not depend on \phi, and \phi dependence of asymmetries have been studied in previous measurements, so change the line to "...its Q$^2$, $x_B$, and t ...". Here no need to have "-t".
line 130 - no need for minus sign in front to of "t", you are not quoting a value
line 152 - at the trigger level CLAS cannot discriminate between negatively and positively charged pions, so remove word "negative" in front of "pion"
line 154 - better to say "...three regions of drift chambers ...". Each region has many layers, total of 34
line 183 - there is an additional space between the word "target" and coma
line 235 - it should be " the total systematic uncertainty was ..."
line 256 and Fig. 4 - I am not sure there is an "approved" convention on how count panels on a figure, but it might be better to explicitly define which panels, instead of saying first five panels, or panels 1-5.
line 266, line 340 - discussions of t-slope and axial charge, while it clearly there will be connection between t-slope, spatial position towards center and the axial charge, it is not clear to me how large t/Q2 plays here for the presented simplistic model at leading twist/leading order. Paragraph on page 1, line 45, clearly states that this process is valid for t/Q2 << 1, is not it. Some explanations are needed in addition to the axial charge distribution.  

Thanks, Stepan