4 Light Scalar Mesons ∗

The crucial points of physics of light scalar mesons are discussed. The special attention is given to the chiral shielding of lightest scalar mesons and the production of the well established light scalar mesons in the φ radiative decays. Arguments in favor of the four-quark model of the a 0 (980) and f 0 (980) mesons are given. To discuss actually the nature of the putative nonet of the light scalar mesons: the pu-tative f 0 (600) (or σ(600)) and κ(700 − 900) mesons and the well established f 0 (980) and a 0 (980) mesons, one should explain not only their mass spectrum, particularly the mass degeneracy of the f 0 (980) and a 0 (980) states, but answer the next real challenges [1]. 1. The copious φ → γf 0 (980) decay and especially the copious φ → γa 0 (980) decay, which looks as the decay plainly forbidden by the Okubo-Zweig-Izuka (OZI) rule in the quark-antiquark model a 0 (980) = (u¯ u − d ¯ d)/ √ 2. 2. Absence of J/ψ → a 0 (980)ρ and J/ψ → f 0 (980)ω with copious J/ψ → a 2 (1320)ρ, J/ψ → f 2 (1270)ω, J/ψ → f