Eur. Phys. J. C (2010) 65: 467-473
https://doi.org/10.1140/epjc/s10052-009-1206-9

Regular Article - Theoretical Physics

J/ψ→VP decays and the quark and gluon content of the η and η ^′

Grup de Física Teòrica and IFAE, Universitat Autònoma de Barcelona, 08193, Bellaterra (Barcelona), Spain

^* e-mail: Rafel.Escribano@ifae.es

Received: 8 September 2009
Published online: 17 November 2009

Abstract

The η–η ^′ pseudoscalar mixing angle and the gluonium content of the η ^′ meson are deduced from an updated phenomenological analysis of J/ψ decays into a vector and a pseudoscalar meson. In absence of gluonium, the value of the mixing angle in the quark-flavor basis is found to be φ _P =(40.7±2.3)°. In presence of gluonium, the values for the mixing angle and the gluonic content of the η ^′ wave function are φ _P =(44.6±4.4)° and , respectively. The newly reported values of B(J/ψ→ρ π) by the BABAR and BES Collaborations are crucial to get a consistent description of the data.