Revisiting Scalar Glueballs

It is commonly believed that the lowest-lying scalar glueball lies somewhere in the isosinglet scalar mesons $f_0(1370), f_0(1500)$ and $f_0(1710)$ denoted generically by $f_{0}$. In this work we consider lattice calculations and experimental data to infer the glue and $q\bar q$ components of $f_0$. These include the calculations of the scalar glueball masses in quenched and unquenched lattice QCD, measurements of the radiative decays $J/\psi\to\gamma f_{0}$, the ratio of $f_{0}$ decays to $\pi\pi$ and $K\bar K$, the ratio of $J/\psi$ decays to $f_0(1710)\omega$ and $f_0(1710)\phi$, the $f_0$ contributions to $B_s\to J/\psi\pi^+\pi^-$, and the near mass degeneracy of $a_0(1450)$ and $K_0^*(1430)$. All analyses suggest the prominent glueball nature of $f_0(1710)$ and the flavor octet structure of $f_0(1500)$.