OPT-IN:Extraction of A^sin(Ï)_LU moments from the hard exclusive Ï^+ channel off the unpolarized hydrogen target in a wide range of kinematics

[Volker Burkert]

Hi Stefan ey al.,

The paper is well written and I have only a few minor suggestions. 

1) Abstract - Generally it is not a good practice to define the many acronyms in the abstract. 
                     It is better to limit the abstract to the process that has been studies and the results. 
                     The range in -t is given as ups to 8 GeV^2, but in Fig. 5 the last bin is centered 
                     at -t = 6.6GeV^2.  I suggest to use max -t = 6.6GeV^2. 

Page 1, right column (r.c.): not clear why chiral-odd GPDs are needed to explain only 
            "... LARGE beam- and target-spin asymmetries".  

Page 4, r.c. The maximum -t = 8.0GeV^2 should be replaced with -t=6.6GeV^2 as there are no
                     horizontal error bars shows that could justify the maxim -t of 8GeV^2. 
             r.c.  "The data is binned in ...." should be "The data ARE binned ...." as "data is plural of datum" 
             r.c. "The t-dependence of ... clearly shows that it is constrained to zero for forward kinematics". 
                    This may well be true, but the minimum asymmetry is shown as 0.06 in Fig.4 when the 
                    maximum is only 0.1. The data don't allow to draw that conclusion.     

Page 5, r.c. "The data WILL provide important constraints .."   => "The data provide important constraints.."

That is all,
  Good luck with the PRL. 
Volker