Nonet Classi cation of Scalar/Isoscalar Resonances in the Mass Region below 1900 MeV: Observation of the Lightest Scalar Glueball

Here we summarize the results of the investigation of the IJ = 00 wave [1-3]: this investigation is devoted to the search for the lightest scalar glueball. In Refs. [1, 2], the q q-nonet classi cation of the scalar/isoscalar states is performed in the mass region below 1900 MeV basing on the following data: GAMS data for p! 0 n [4], n [5], n [6]; CERN-M unich data for p! + n [7]; Crystal Barrel data for p p ! 0 0 , 0 0 , 0 [8, 9]; BNL data for ! KK [10]. The nonet classi cation of the states and search for extra states look like the only way for the identi cation of lightest glueballs. The 00-wave is analyzed in Refs. [1, 2] in terms of theK-matrix elements which are presented in the form: