Impact of pi N --> pi pi N data on determining high-mass nucleon resonances

Abstract

Motivated by an experimental proposal for the measurement of the pi N --> pi pi N reactions at J-PARC, we examine a potential impact of the pi N --> pi pi N cross section data on the determination of the resonance parameters of the high-mass N* states. For this purpose, we make use of the ANL-Osaka dynamical coupled-channels model, which has been developed recently by a combined analysis of the unpolarized as well as polarized observables of pion- and photon-induced pi N, eta N, K Lambda, and K Sigma production reactions off a proton target. We present predictions for the pi N --> pi pi N total cross sections and invariant mass distributions, and demonstrate that the pi N --> pi pi N differential cross section data can indeed be a crucial source of information for understanding N* --> pi Delta, rho N, sigma N --> pi pi N decay of the high-mass N* states.