Dynamical coupled channel calculation of pion and omega meson production

A dynamical coupled channel approach is used to study $\pi$ and $\omega$–meson production induced by pions and photons scattering from the proton. Six intermediate channels including $\pi N$, $\eta N$, $\pi \mathrm{\Delta }$, $\sigma N$, $\rho N$ and $\omega N$ are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to data for $\pi N\to \pi N$, $\gamma N\to \pi N$, $\pi^- p \to \omega n$,and$\gamma p \to \omega p$ reactions at center-of-mass energies from threshold to $W<2.0$ GeV. The $T$ matrix determined in these fits is used to calculate the photon beam asymmetry for $\omega$-meson production and the $\omega N\to \omega N$ total cross section and $\omega N$ scattering lengths.