Apr 8 – 12, 2024
Maison MINATEC, Grenoble, FRANCE
Europe/Paris timezone

Accessing Generalized Parton Distributions through 2 -> 3 exclusive processes

Apr 9, 2024, 11:20 AM
Maison MINATEC, Grenoble, FRANCE

Maison MINATEC, Grenoble, FRANCE

3 Parv. Louis Néel, 38054 Grenoble
Regular parallel talk WG5: Spin and 3D Structure WG5


Samuel Wallon (IJCLab)


We review our results on a new class of 2 -> 3 exclusive processes, as a probe of both chiral-even and chiral-odd quark GPDs. We consider the exclusive photoproduction of a photon-meson pair, in the kinematics where the pair has a large invariant mass, described in the collinear factorization framework. We cover the whole kinematical range from medium energies in fixed target experiments to very large energies of colliders, by considering the experimental conditions of JLab 12-GeV, COMPASS, future EIC and LHC (in ultra-peripheral collisions) cases. Our analysis covers neutral and charged rho-mesons, as well as charged pions. In the case of the rho-meson, depending on its polarization, this provides access to either chiral-even or chiral-odd GPDs, at leading twist. We find that the order of magnitude of the obtained cross sections are sufficiently large for a dedicated experimental analysis to be performed, especially at JLab. Furthermore, we compute the linear photon beam polarization asymmetry, which we find to be sizeable, in the case of a longitudinally polarized rho meson or of a charged pion. These predictions are obtained for both asymptotic distribution amplitude (DA) and holographic DA.

Primary authors

Samuel Wallon (IJCLab) Goran Duplancic (Boskovic Inst. Zagreb) Saad Nabeebaccus (IJCLab) Kornelija Passek-Kumericki (Bostkovic Inst. Zagreb) Bernard Pire (CPHT) Lech Szymanowski (NCBJ, Warsaw)

Presentation materials