Scalar glueball and coupled channels

A new method is proposed for analyzing the scalar meson scattering amplitude by means of its uniforming. This gives a compact formula for the analysis of the isoscalar s-wave pion-pion scattering in terms of the multipole resonance description. In order to extend the scattering matrix from the physical region to all unphysical sheets in the energy variable, the unitarity relation was used. It is shown that a simple description of the partial wave scattering amplitude can be achieved even in the presence of resonant states and other strongly coupled scattering channels. (Z.S.) 8 refs