Easy as $\pi^o$: On the Interpretation of Recent Electroproduction Results

Abstract

Exclusive $\pi^o$ electroproduction from nucleons was first suggested by Ahmad, Goldstein and Liuti for extracting from experimental data the tensor charge, transversity and other quantities related to chiral odd combinations of generalized parton distributions. We now explain the details of the process: {\it i)} the connection between the helicity description and the cartesian basis; {\it ii)} the dependence on the momentum transfer squared, $Q^2$, and {\it iii)} the angular momentum, parity, and charge conjugation constraints ($J^{PC}$ quantum numbers).