A lattice study of the masses of singlet 0++ mesons

TL;DR

This study uses unquenched lattice QCD to compute the masses of flavor singlet 0++ mesons, revealing a suppression of the lightest meson mass compared to quenched glueball states, with implications for understanding meson structure.

Contribution

It provides the first unquenched lattice QCD calculation of flavor singlet 0++ meson masses using multiple gauge actions and operator types, highlighting mass suppression phenomena.

Findings

Lightest 0++ meson mass is suppressed relative to quenched glueball.

Both fermionic and glueball operators are effective in state creation.

Results suggest possible physical reasons for mass suppression.

Abstract

We compute the masses of the flavour singlet 0++ mesons using (n_f=2) unquenched lattice QCD with the Iwasaki and Wilson gauge actions. Both fermionic and glueball interpolating operators are used to create the states. The mass of the lightest 0++ meson is suppressed relative to the mass of the 0++ glueball in quenched QCD at an equivalent lattice spacing. We discuss two possible physical reasons for this.