Pseudoscalar mixing in J/psi and psi(2S) decay

TL;DR

This paper investigates the pseudoscalar mixing in J/psi and psi(2S) decays using experimental data and a phenomenological model, determining the mixing angle and gluonic content of eta and eta prime mesons.

Contribution

It provides a detailed analysis of pseudoscalar mixing angles and gluonic content in eta and eta prime mesons based on decay data, incorporating both quark and gluonic components.

Findings

Mixing angle of -14 degrees when considering only quark content.

Eta meson favors light quark composition.

Gluonic content of eta prime is Z_{eta prime}^2=0.30±0.24.

Abstract

Based on the branching fractions of J/psi(psi(2S))-> VP from different collaborations, the pseudoscalar mixing is extensively discussed with a well established phenomenological model. The mixing angle is determined to be -14 degree by fitting to the new world average if only quark content is considered. After taking into account the gluonic content in eta and eta prime simultaneously, the investigation shows that eta favors only consisting of light quarks, while the gluonic content of eta prime is Z_{eta prime}^2=0.30\pm0.24.