Dynamical coupled channel calculation of pion and omega production

The dynamical coupled channel approach developed at the Excited Baryon Analysis Center is extended to include the $\omega N$ channel to study $\pi$ and $\omega$--meson production induced by scattering pions and photons from the proton. Six intermediate channels, including $\pi N$, $\eta N$, $\pi\Delta$, $\sigma N$, $\rho N$, $\omega N$, are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to the 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. The calculated beam asymmetry is in good agreement with the observed in the range of energies near threshold to $W < 2.0$ GeV.