Gluonium and the 0++ spectrum

We suggest that the σ (broad ππ s-wave states below 1 GeV) and the S¹(0.98) can be interpreted by a mixing between a scalar gluonium and an SU(2) singlet meson with a mixing angle of the order of 14°–19°. The decays of the σ and of the S¹ into a pseudoscalar pair are shown to be dominated by their gluon component. In this way, one expects a universal coupling of the σ and of the S¹ to ππ and KK?. The above scheme is confronted to the ψ-decays and to some scattering data. A radial excitation assignment of the G(1.6) is discussed.