Light Scalar Mesons from Phi to Psi

Abstract

The following topics are considered. 1) Confinement, chiral dynamics, and light scalar mesons. 2) Chiral shielding of the $\sigma(600)$. 3) The $\phi$ meson radiative decays about nature of light scalar resonances. 4) The $J/\psi$ decays about nature of light scalar resonances. 5) The $a_0(980)\to\gamma\gamma$ and $f_0(980)\to\gamma\gamma$ decays about nature of light scalar resonances. 6) New round in $\gamma\gamma\to\pi^+\pi^-$, the Belle data. Arguments in favor of the four-quark model of the $a_0(980)$ and $f_0(980)$ mesons are given.