The structure of the light scalar mesons and QCD sum rules

Abstract

The structure of the light scalar mesons is elucidated by the investigation of the S-matrix poles and the q-qbar spectral density in a coupled channel model that includes pi-pi, K-Kbar and q-qbar channels. It is shown that the dynamical origin of the sigma and f0(980) mesons is consistent with the observed spectrum of the scalar states. The K-Kbar molecular picture of the f0(980) is in good agreement with recent experimental data on the decay phi - gamma pi pi from Novosibirsk.

Comments: 5 pages, 3 PostScript figures; presented at Meson 2000, Cracow, Poland, May 19--23, 2000; to be published in Acta Phys. Pol. B