The scalar glueball from BESIII data on radiative $J/\psi$ decays
A coupled-channel analysis of data on radiative $J/\psi$ decays constrained by further data reveals the existence of ten scalar isoscalar resonances. Five seem to be mainly SU(3) singlet, five mainly octet states. Pure octet mesons should not be produced in radiative $J/\psi$ decays. But their yield is significant and peaks at 1865 MeV with no background. Singlet mesons are produced over a wide mass range and peak at the same mass: The peak is interpreted as the scalar glueball of lowest mass.