Electromagnetic transition form factors of light mesons

We study selected meson transition processes and associated form factors within a model of QCD based on the Dyson-Schwinger equations truncated to the ladder-rainbow level. The infrared structure of the ladder-rainbow kernel is described by two parameters, the ultraviolet behavior is fixed by the one-loop renormalization group behavior of QCD. The work is restricted to the u and d quark sector and allows a Poincare-covariant study of the radiative decays rho-->pigamma, omega-->pigamma, and pi(0)-->gammagamma. Particular attention is paid to the form factors for the associated transitions gamma*pi(0)-->gamma, gamma*pi(0)-->gamma*, gamma*pi-->rho, and gamma*rho-->pi. The latter two processes are of interest as contributors to meson electroproduction from hadronic targets away from the s-channel resonance region. We use the present QCD model to explore limitations to the assumption that coupling to a t-channel virtual (q) over barq correlation can be modeled as meson exchange.