Imaging quark transverse spin distributions via exclusive pseudoscalar meson electroproducton with CLAS at Jefferson Lab.

One of the major experimental research programs of the Jefferson Lab CLAS Collaboration is deeply virtual pseudoscalar meson electroproduction. These reactions are uniquely sensitive to the transversity generalized parton distributions (GPD) E_T, and H_T, which are related to quark transverse spin densities in the nucleon. By observing different mesons one can obtain distributions for each quark flavor. Experimental results on exclusive π⁰ and η electroproduction at electron energy near 6 GeV, obtained by the  CLAS collaboration, will be presented, and discussed in terms of their separation into generalized form factors (GFF) and GPDs of u and d quark flavors. These in turn can be related to the density of polarized u and d quarks in an unpolarized nucleon. The resulting analysis relating to transversity spin densities of the nucleon’s u and d quark flavors will be presented. Further plans for measurements at higher beam energies at CLAS, and the planned analysis in terms of GFFs, and GPDs will be discussed.