  Meson production on the proton is described in a coupled channels K-matrix
approach. Both hadronic and photonic scenarios are taken into account on the
same theoretical footing. At tree-level the Born amplitudes are obtained from
an effective Lagrangian with phenomenologically adjustable coupling constants.
The spectral distributions, resonances and their width and the background
contributions are obtained within the same approach, thus accounting properly
for interference effects. Applications to omega- and associated strangeness
production on the proton are discussed.
