Isoscalar meson spectroscopy from lattice quantum chromodynamics

Abstract

The isoscalar mesons are bound states of quarks and anti-quarks with particularly simple up and down quark flavour structure. Because of this simplicity, these mesons can have the same quantum numbers as other states predicted by QCD made up solely of gluons; the glueballs. Since they share common quantum numbers, QCD allows them to mix and understanding experimental signatures for these states is therefore very challenging since it is unclear whether particles observed in experiments are glueballs or simpler quark-anti-quark admixtures.

This project will attempt the first spectroscopy determination of isoscalar mesons using lattice QCD combined with a powerful new method developed by the Hadron Spectrum Collaboration called `distillation`. The computation will make use of the collaboration`s large ensemble of gauge field configurations generated on an anisotropic lattice with the full quark-field dynamics included in the importance sampling measure. The method will be used to determine the lowest- lying states in this spectrum with unprecedented precision and examine whether the observed experimental states can be wholly explained as quark-anti-quark bound states.