Decays of the light hybrid meson 1−+

Abstract

The full width of the light isovector hybrid meson HV with spin-parities 1−+ and content (u¯gu−d¯gd)/2 is evaluated by considering the decays HV→ρ±π∓, b1±π∓, f1(1285)π, f1(1420)π, ηπ, and η′π. 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 Γ[HV]=(109.7±16.0) MeV of the hybrid meson comes from the processes HV→ρ±π∓ partial width of which amounts to ≈67 MeV. The effects of the decays HV→b1π and HV→f1π,f1′π are also sizeable: Their partial widths are equal to 13 MeV and 20 MeV, respectively. The decays to ηπ and η′π mesons are subdominant reactions, nevertheless they form ≈9% of the full width Γ[HV]. Results obtained in this work may be interesting to unravel the tangle of predictions about HV existing in the literature, as well as useful in analyses of different resonances. Published by the American Physical Society 2025