Singlet-octet-glueball mixing of scalar mesons

TL;DR

This paper investigates the mixing of scalar mesons with a scalar glueball by analyzing decay data, suggesting a significant glueball component around 1965 MeV, and providing insights into the composition of various scalar resonances.

Contribution

It provides a detailed analysis of scalar meson-glueball mixing angles and estimates the scalar glueball content in several mesons based on decay data.

Findings

Small glueball component in $f_0(1370)$ and $f_0(1500)$

Significant glueball fractions in higher mass states

Estimated scalar glueball at 1965 MeV with 370 MeV width

Abstract

The mixing angles between scalar isoscalar resonances and a scalar glueball are determined from their decays into two pseudoscalar mesons. For $f_0(1370)$ and $f_0(1500)$, at most a small glueball component is admitted by the data. The decay modes of $f_0(1710)$, $f_0(1770)$, $f_0(2020)$, and $f_0(2100)$ require significant glueball fractions. Above this mass, the errors in the decay frequencies become too large to extract a glueball component. The summation of all observed glueball fractions up to 2100\,MeV yields (78\er18)\%. The glueball fractions as function of the mass are consistent with a scalar glueball at 1965\,MeV and a width of 370\,MeV as suggested by a measurement of the yield of scalar isoscalar mesons in radiative $J/\psi$ decays.