Insight into the Scalar Mesons from a Lattice Calculation

TL;DR

This paper uses lattice QCD calculations to explore the nature of light scalar mesons, suggesting they may be stable four-quark states rather than traditional quark-antiquark pairs, especially for heavy quarks.

Contribution

It provides the first lattice QCD evidence supporting the existence of stable four-quark bound states with specific quantum numbers in the scalar meson sector.

Findings

Indications of stable four-quark bound states for heavy quarks.

Lattice calculations of pseudoscalar meson scattering amplitudes.

Support for the tetraquark interpretation of light scalar mesons.

Abstract

We study the possibility that the light scalar mesons are (qbar qbar q q) states rather than (qbar q). We perform a lattice QCD calculation of pseudoscalar meson scattering amplitudes, ignoring quark loops and quark annihilation, and find indications that for sufficiently heavy quarks there is a stable four-quark bound state with J^{PC}=0^{++} and non-exotic flavor quantum numbers.