Meson and tetra-quark mixing

TL;DR

This paper investigates the mixing between meson and tetra-quark states using an effective QCD Hamiltonian, revealing significant effects for scalar hadrons and providing improved spectral predictions.

Contribution

It introduces a method to compute and diagonalize mixing matrix elements within an effective QCD model, enhancing understanding of low-lying hadron spectra.

Findings

Significant mixing effects for scalar hadrons.

Minimal mixing effects for 1^{--} states, consistent with ideal mixing.

Provides improved predictions for low-lying isoscalar spectra.

Abstract

The mixing between q-qbar meson and qqbar-qqbar tetra-quark states is examined within an effective QCD Coulomb gauge Hamiltonian model. Mixing matrix elements of the Hamiltonian are computed and then diagonalized yielding an improved prediction for the low-lying J^{PC} = 0^{+/- +}, 1^{--} isoscalar spectra. Mixing effects were found significant for the scalar hadrons but not for the 1^{--} states, which is consistent with the ideal mixing of vector mesons. A perturbative assessment of the exact QCD kernel is also reported.