Double and single pion photoproduction within a dynamical coupled-channels model

TL;DR

This paper presents predictions for double pion photoproduction cross sections using a dynamical coupled-channels model, analyzing various mechanisms and their interplay to understand the reaction dynamics up to W<1.7 GeV.

Contribution

The study extends a fixed dynamical coupled-channels model to predict double pion photoproduction, analyzing mechanisms and identifying key parameters for future combined data analysis.

Findings

Predicted double pion photoproduction cross sections up to W<1.7 GeV.

Analyzed the roles of different reaction mechanisms.

Identified key model parameters for future studies.

Abstract

Within a dynamical coupled-channels model which has already been fixed from analyzing the data of the pi N -> pi N and gamma N -> pi N reactions, we present the predicted double pion photoproduction cross sections up to the second resonance region, W< 1.7 GeV. The roles played by the different mechanisms within our model in determining both the single and double pion photoproduction reactions are analyzed, focusing on the effects due to the direct gamma N -> pi pi N mechanism, the interplay between the resonant and non-resonant amplitudes, and the coupled-channels effects. The model parameters which can be determined most effectively in the combined studies of both the single and double pion photoproduction data are identified for future studies.