  The photo- and electroproduction of eta, eta-prime mesons on nucleons are
investigated within a relativistic chiral unitary approach based on coupled
channels. The s-wave potentials for electroproduction and meson-baryon
scattering are derived from a chiral effective Lagrangian which includes the
eta-prime as an explicit degree of freedom and incorporates important features
of the underlying QCD Lagrangian such as the axial U(1) anomaly. The effective
potentials are iterated in a Bethe-Salpeter equation and cross sections for
eta, eta-prime photo- and electroproduction from nucleons are obtained. The
results for the eta-prime photoproduction cross section on protons reproduce
the appearance of an S_{11} resonance around 1.9 GeV observed at ELSA. The
inclusion of electromagnetic form factors increases the predicted eta
electroproduction cross sections on the proton, providing a qualitative
explanation for the hard form factor of the photocoupling amplitude observed at
CLAS.
