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

TL;DR

This paper analyzes $J/\psi$ decays to determine the mixing angle and gluonic content of the $\eta'$ meson, providing updated phenomenological values for these parameters based on decay data.

Contribution

It offers the first updated phenomenological extraction of the $\eta$-$\eta'$ mixing angle and gluonium content from $J/\psi$ decay data.

Findings

Mixing angle $\phi_P = (44.5 \pm 4.3)^{\circ}$

Gluonic content $Z_{\eta'}^2 = 0.28 \pm 0.21$

Updated values improve understanding of $\eta'$ structure.

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.