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

TL;DR

This paper updates the eta-eta' mixing angle using J/psi decay data, confirming the importance of omega-phi mixing corrections, but recent experimental results challenge existing models.

Contribution

It provides an updated phenomenological analysis of eta-eta' mixing angle from J/psi decays, emphasizing the role of omega-phi mixing corrections and discussing recent experimental challenges.

Findings

Mixing angle θ_P = -16.9 ± 1.7 degrees confirmed.

Corrections due to omega-phi mixing are crucial.

Recent J/psi decay measurements complicate data description.

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 $\omega$-$\phi$ 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.