[Clascomment] OPT-IN:First measurement of hard exclusive pi-Delta++ electroproduction beam-spin asymmetries off the proton

[Sebastian Kuhn]

Very nice paper. One caveat: I am not sure how well-founded the (rather long) interpretation section (starting at line 267) is. In particular, the idea to relate the measured BEAM SSAs to the quark helicity in a polarized TARGET Nucleon may need more explanation (it seems rather indirect). The only reference given is Kroll et al. - do you have any other theorists who can support this conclusion about the d helicity? Do Kroll et al.? (Of course, for DSA it is very different). Not a showstopper, but just wanted to make sure that you can defend that conclusion (a simple argument would be nice, e.g., how is the BSA related to the initial polarization of the struck nucleon?)