Update of eta-eta' mixing from J/psi->VP decays

Abstract

The $\eta$-${\eta }^{\prime }$ mixing angle is deduced from an updated phenomenological analysis of $J/\psi$ decays into a vector and a pseudoscalar meson. Corrections due to non-ideal $\omega$-$\varphi$ mixing are confirmed to be crucial to find ${\theta }_P=(-16.9\pm 1.7{)}^{\circ }$, in agreement with most recent analyses. The newly reported values of $B(J/\psi \to \rho \pi )$ by the BABAR and BES Collaborations make more difficult a reasonable description of data.

Comments: 6 pages, uses aipproc style. Talk presented at SCADRON 70: Workshop on "Scalar Mesons and Related Topics", Lisbon, Portugal, 11-16 February 2008