Single diffractive hard exclusive processes for the study of generalized parton distributions*

Generalized parton distributions (GPDs) are important non-perturbative functions that provide tomographic images of the partonic structures of hadrons. We introduce a type of exclusive processes for a better study of GPDs, which we refer to as single diffractive hard exclusive processes (SDHEPs), and give a general proof for their factorization into GPDs. We demonstrate that the SDHEP is not only sufficiently generic to cover all known processes but also well motivated for searching for new processes for extracting GPDs. Importantly, we also examine the sensitivity of the SDHEP to the parton momentum fraction $x$ dependence of GPDs, and demonstrate quantitatively with two processes that can be readily measured at J-PARC/AMBER and JLab, respectively.