On the Nature of f0(400-1200)

We discuss about the nature of f₀(400-1200) which we decompose into three parts, i.e., t-channel ρ meson and f₂(1270) meson exchange plus an additional s-channel resonance f₀(X). Below 1.2GeV of ππ invariant mass, t-channel ρ meson exchange can explain the I=2 ππ S-wave scattering very well. However, the f₂(1270) meson exchange must be considered for the ππ invariant mass above 1.2GeV. With the t-channel ρ meson and f₂(1270) meson exchange fixed by the isotensor ππ→ππ S-wave scattering, we re-fit the CERN-Mülich(CM) data on ππ scattering to get parameters for the f₀(X). We find that it is necessary to introduce a broad 0⁺⁺ resonance with a pole about 1.6-1.7GeV.