Decay width of light quark hybrid meson from the lattice

Abstract

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