Dynamical coupled-channels approach to electroweak meson productions on nucleon and deuteron

Abstract

I overview our recent activity with the Argonne-Osaka dynamical coupled-channels (DCC) approach that provides a unified description of various electroweak meson productions on single nucleon and nucleus. First I discuss the DCC model of a single nucleon. The DCC model has been developed through a comprehensive analysis of $\pi N, \gamma N\to \pi N, \eta N, K\Lambda, K\Sigma$ reaction data. The model has been further extended to finite $Q^2$ region by analyzing pion electroproduction data, and to neutrino-induced reactions using the PCAC relation. Next I discuss applications of the DCC model to electroweak meson productions on the deuteron. We consider impulse mechanism supplemented by final state interactions (FSI) due to $NN$ and meson-nucleon rescatterings. Using this model, I discuss FSI corrections needed to extract $\gamma$-neutron reaction observables from $\gamma d\to \pi NN$, and a novel method to extract $\eta N$ scattering length from $\gamma d\to \eta pn$. I also discuss FSI corrections on the existing neutrino-nucleon pion production data that had been extracted from neutrino-deuteron data.