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

[Victor Mokeev]

 Dear Colleagues,

 Thank you for the very nice new data set! It extend considerably our capability to determine resonance electrocouplings, in particular, for the resonances with masses above 1.6 GeV for which the available results are rather limited.

 I have the proposal in regards of the data presentation. The asymmetries A_{LL}, A_{UL} are unambiguously determined by the structure functions sigma_{t}, sigma_{l}, sigma_{tt}, sigma{tl},
sigma_{tl'}, sigma{tt'}. All physics related to the reaction dynamics and hadron structure is encoded inside these structure functions. Dependence from phy comes from QED, well know and can not be the subject of our exploration, except for the data quality checks.

May be better to report the aforementioned structure functions sigma_{i} derived  from the A_{UL}, A_{LL} instead of the quantities A_{UL} and A_{LL}?  The sigma_{i} structure function depend from W,Q^2,theta only. It would be more compact way for the presentation of the huge massive of the data.
Furthermore, namely these structure functions are needed for the physics analyses aimed on determining N* parameters.


 I also want to let you know on the recent CLAS results on resonance electrocouplings from Npipi channel in the kinematic area covered by your analysis you may want to mention in the introductory and/or summary parts:

V.I.Mokeev, V.D.Burkert, D.S. Carman et al., arXiv1509.05460[nucl-ex], submitted to Phys Rev C
V.I. Mokeev and I.G. Aznauryan, Int. J. Mod. Phys. Conf. Ser. 26 1460080 (2014).


  Thank you!


    Best Regards,
                          Victor