Decays of the $\hat{\rho }(1^{-+})$ Exotic Hybrid and $\eta$-${\eta }^{\prime }$ Mixing

Abstract

QCD sum-rules are used to calculate the $\hat{\rho }(1^{-+})\to \pi \eta ,\pi {\eta }^{\prime }$ decay widths of the exotic hybrid in two different $\eta -{\eta }^{\prime }$ 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 ${\Gamma }_{\hat{\rho }\to \eta \pi }\approx 250MeV$ is large compared with the decay width ${\Gamma }_{\hat{\rho }\to {\eta }^{\prime }\pi }\approx 20MeV$. These results provide some insight into $\eta$-${\eta }^{\prime }$ mixing and hybrid decay features.

Comments: latex2e, 11 pages with 4 embedded eps figures. v 2 corrects reference [5] and minor error in equation (11)