Decay width of light quark hybrid meson from the lattice

TL;DR

This study uses lattice QCD to investigate the spectrum and decay properties of a spin-exotic hybrid meson, providing estimates for its mass and decay widths, and validating decay amplitude calculations against experimental data.

Contribution

First lattice QCD calculation of the decay widths of a light quark hybrid meson with validation against experimental data.

Findings

Hybrid meson mass estimated at 2.2 GeV

Partial decay width to πb₁ is approximately 400 MeV

Partial decay width to πf₁ is approximately 90 MeV

Abstract

Lattice QCD with $N_f=2$ flavours of sea quark is used to explore the spectrum and decay of a $J^{PC}=1^{-+}$ spin-exotic hybrid meson. We test lattice determination of S-wave decay amplitudes at threshold using $b_1 \to \pi \omega$ where agreement with data is found. We find a hybrid meson state at 2.2(2) GeV with a partial width to $\pi b_1$ of 400(120) MeV and to $\pi f_1$ of 90(60) MeV.