A coupled-channel analysis has been performed to identify the spectrum of scalar mesons. The data include BESIII data on radiative $J/psi$ decays into $pi^0pi^0$,$K_SK_S$, $etaeta$, and $omegaphi$, 15 Dalitz plots from $bar pN$ annihilation at rest at LEAR, the CERN-Munich multipoles for $pipi$ elastic scattering, the $S$-wave from BNL data on $pipi$ scattering into $K_SK_S$, from GAMS data on $pipito pi^0pi^0, etaeta$, and $etaeta$, and NA48/2 data on low-mass $pipi$ interactions from $K^pmtopipi e^pm u$ decays. 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. The production of isoscalar resonances with a large octet component should be suppressed in radiative $J/psi$ decays. However, in a limited mass range centered at 1900,MeV, these mesons are produced abundantly. Mainly-singlet scalar resonances are produced over the full mass range but with larger intensity at 1900,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.
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