[Clascomment] OPT-IN:Target and Beam-Target Spin Asymmetries in exclusive Ï+ and Ïâ electroproduction with 1.6 to 5.7 GeV elec trons

[bosted at jlab.org]

Dear Victor,
   Thank-you for your comment. We would definitely have reported reduced
cross sections instead of asymmetries if
a) we had spin-averaged cross sections available in each bin.
b) we had full phi* coverage (needed to dis-entangle cos(pi) from
cos(2phi), etc terms. Unfortunately, our phi* coverage is very
limited in some of the kinematic bins.
   We think the best strategy is to include the asymmetries directly in a
global fit. I am working on such a simple empirical  fit myself, but it
is beyond the scope of the present paper (and is far from being done in
any case).
   Yours, Peter


>  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
>