Identification of a Scalar Glueball

TL;DR

This study uses a comprehensive coupled channel approach to identify scalar glueballs in meson-meson interactions up to 2 GeV, confirming the f_0(1710) and a 1.6 GeV pole as glueball candidates.

Contribution

First-time inclusion of multiple meson channels in coupled channel analysis to identify scalar glueballs consistent with lattice QCD predictions.

Findings

f_0(1710) identified as a scalar glueball candidate

Pole at 1.6 GeV linked to glueball contribution

f_0(1370) remains a pure octet state

Abstract

We have performed a coupled channel study of the meson-meson S-waves involving isospins (I) 0, 1/2 and 3/2 up to 2 GeV. For the first time the channels \pi\pi, K\bar{K}, \eta\eta, \sigma\sigma, \eta\eta', \eta'\eta', \rho\rho, \omega\omega, \omega\phi$, \phi\phi, a_1\pi and \pi^*\pi are considered. All the resonances with masses below 2 GeV for I=0 and 1/2 are generated by the approach. We identify the f_0(1710) and a pole at 1.6 GeV, which is an important contribution to the f_0(1500), as glueballs. This is based on an accurate agreement of our results with predictions of lattice QCD and the chiral suppression of the coupling of a scalar glueball to \bar{q}q. Another nearby pole, mainly corresponding to the f_0(1370), is a pure octet state not mixed with the glueball.