Isoscalar meson spectroscopy from lattice QCD

TL;DR

This study uses lattice QCD to precisely analyze the spectrum of isoscalar mesons, including high-spin and exotic states, overcoming previous computational challenges and revealing detailed flavor mixing and mass scale insights.

Contribution

The paper introduces a novel quark field construction enabling efficient inclusion of quark-annihilation effects in lattice QCD for isoscalar mesons.

Findings

Identified high-spin and exotic isoscalar mesons with high statistical precision.

Extracted hidden-flavor mixing angles showing mostly ideal mixing, with some large mixing cases.

Exotic JPC isoscalar states appear at similar mass scales to isovector counterparts.

Abstract

We extract to high statistical precision an excited spectrum of single-particle isoscalar mesons using lattice QCD, including states of high spin and, for the first time, light exotic JPC isoscalars. The use of a novel quark field construction has enabled us to overcome the long-standing challenge of efficiently including quark-annihilation contributions. Hidden-flavor mixing angles are extracted and while most states are found to be close to ideally flavor mixed, there are examples of large mixing in the pseudoscalar and axial sectors in line with experiment. The exotic JPC isoscalar states appear at a mass scale comparable to the exotic isovector states.