Eta' gluonic content and J/psi->VP decays

Abstract

The $\eta$-$\eta^\prime$ pseudoscalar mixing angle and the gluonium content of the $\eta^\prime$ meson are deduced from an updated phenomenological analysis of $J/\psi$ decays into a vector and a pseudoscalar meson. The values for the mixing angle and the gluonic content of the $\eta^\prime$ wave function are $\phi_P=(44.5\pm 4.3)^\circ$ and $Z^2_{\eta^\prime}=0.28\pm 0.21$, respectively.