Decays of the light hybrid meson $ {1}^{-+}$

The full width of the light isovector hybrid meson $ {H}_{\mathrm{V}}$ with spin-parities $ {1}^{-+}$ and content $ (\overline{u}gu-\overline{d}gd)/\sqrt{2}$ is evaluated by considering the decays $ {H}_{\mathrm{V}}\to {\rho }^{\pm }{\pi }^{\mp }$, $ {b}_{1}^{\pm }{\pi }^{\mp }$, $ {f}_{1}(1285)\pi $, $ {f}_{1}(1420)\pi $, $ \eta \pi $, and $ {\eta }^{\prime }\pi $. To calculate the partial widths of these channels, we use the quantum chromodynamics (QCD) three-point sum rule method which is necessary to determine strong couplings at the corresponding hybrid-meson-meson vertices. It turns out that the main contribution to the full width $ \mathrm{\Gamma }[{H}_{\mathrm{V}}]=(109.7\pm 16.0)\text{}\text{}\mathrm{MeV}$ of the hybrid meson comes from the processes $ {H}_{\mathrm{V}}\to {\rho }^{\pm }{\pi }^{\mp }$ partial width of which amounts to $ \approx 67\text{}\text{}\mathrm{MeV}$. The effects of the decays $ {H}_{\mathrm{V}}\to {b}_{1}\pi $ and $ {H}_{\mathrm{V}}\to {f}_{1}\pi ,{f}_{1}^{\prime }\pi $ are also sizeable: Their partial widths are equal to 13 MeV and 20 MeV, respectively. The decays to $ \eta \pi $ and $ {\eta }^{\prime }\pi $ mesons are subdominant reactions, nevertheless they form $ \approx 9\%$ of the full width $ \mathrm{\Gamma }[{H}_{\mathrm{V}}]$. Results obtained in this work may be interesting to unravel the tangle of predictions about $ {H}_{\mathrm{V}}$ existing in the literature, as well as useful in analyses of different resonances.