2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173448The $η$-$η^\prime$ pseudoscalar mixing angle and the gluonium content of the $η^\prime$ meson are deduced from an updated phenomenological analysis of $J/ψ$ decays into a vector and a pseudoscalar meson. The values for the mixing angle and the gluonic content of the $η^\prime$ wave function are $ϕ_P=(44.5\pm 4.3)^\circ$ and $Z^2_{η^\prime}=0.28\pm 0.21$, respectively.5 pages, uses espcrc2 style. Talk presented at the International Workshop on e+e- collisions from Phi to Psi (PHIPSI08), Laboratori Nazionali di Frascati (Rome), Italy, 7-10 April 2008High Energy Physics - PhenomenologyHigh Energy Physics - Experimenttext