Speaker
Description
rest at LEAR, the CERN-Munich multipoles for $\pi\pi$ elastic scattering, the $S$-wave from BNL data on $\pi\pi$ scattering into $K_SK_S$, and from GAMS data on $\pi\pi\to \pi^0\pi^0, \eta\eta$, and $\eta\eta'$. The analysis reveals the existence of ten scalar isoscalar resonances. The resonances can be grouped into two classes: resonances with a large SU(3) singlet component and those with
a large octet component. Their production of isoscalar resonances with a large octet component is suppressed in radiative $J/\psi$ decays. However, in a limited mass range centered at 1850\,MeV, these mesons are produced abundantly. Mainly-singlet scalar resonances are produced over the full mass range but with larger intensity at 1850\,MeV. The total scalar isoscalar yield in radiative decays into scalar mesons shows a clear peak which is interpreted as the scalar glueball of lowest mass.
