On wide-angle photo- and electroproduction of pions to twist-3 accuracy

Abstract

The wide-angle photo- and electroproduction of pions is investigated within the handbag mechanism in which the ${\gamma }^{(\ast )}N\to \pi N^{\prime }$ amplitudes factorize into subprocess amplitudes,${\gamma }^{(\ast )}q\to \pi q^{\prime }$, and form factors representing $1/x$-moments of generalized parton distributions (GPDs). The subprocess is calculated to twist-3 accuracy taking into account both the 2- and 3-body Fock components of the pion. The cross-sections are compared to experiment and spin-effects are discussed.

Comments: 4 pages, 3 figures; Contribution to the 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON2021)