4th Workshop on Future Directions in Spectroscopy Analysis (FDSA2022)

Theoretical Model of Two-Pion Photoproduction: Part 2

Nov 16, 2022, 4:20 PM

20m

Jefferson Lab

Speaker

Robert Perry (Univerisity of Barcelona)

Description

Photoproduction is an important reaction in studies of hadron spectroscopy. In particular, a study of two-pion photoproduction allows for an investigation of meson resonances in the pi-pi system and also allows one to study the process $\gamma p\to \pi \mathrm{\Delta }$. Under the assumption of single pion exchange, this two-to-three process may be factorized into two sub-processes; a photon dissociation to two (off-shell) pions, and a further two-body $\pi N$ scattering event which brings the system on-shell. This interpretation allows for a description of two-pion photoproduction in terms of the well-known elastic $\pi N$ scattering amplitudes. Augmenting this so-called 'Deck Mechanism' with the $\rho$ resonance leads to a reasonable description of the differential cross section in the vicinity of the $\rho$ resonance. Encouraged by this success, we predict the angular moments of the two-pion system and compare with CLAS data. We also make predictions for the process $\gamma p\to \pi \mathrm{\Delta }$.

Presentation materials

slides.pdf