Decays of the $\hatρ(1^{-+})$ Exotic Hybrid and $η$-$η'$ Mixing

Abstract

QCD sum-rules are used to calculate the $\hatρ(1^{-+})\toπη, πη'$ decay widths of the exotic hybrid in two different $η-η'$ mixing schemes. In the conventional flavour octet-singlet mixing scheme, the decay widths are both found to be small, while in the recently-proposed quark mixing scheme, the decay width $Γ_{\hatρ\toηπ}\approx 250 MeV$ is large compared with the decay width $Γ_{\hatρ\toη^\primeπ}\approx 20 MeV$. These results provide some insight into $η$-$η'$ mixing and hybrid decay features.