The structure of the light scalar mesons and QCD sum rules

The structure of the light scalar mesons is elucidated by the investigation of the S-matrix poles and the q (q) over bar spectral density in a coupled channel model that includes pi pi, K (K) over bar and q (q) over bar chann els. It is shown that the dynamical origin of the sigma and f(0)(980) meson s is consistent with the observed spectrum of the scalar states. The K (K) over bar molecular picture of the f(0)(980) is in good agreement with recen t experimental data on the decay rho --> gamma pi pi from Novosibirsk.