A simple π-η-gh' mixing model for R=Γ (ψ' --> ψπ)/Γ(ψ' --> ψη) and r = Γ(ψ --> η'γ)/Γ(ψ --> ηγ)

A joint description of the ratios r ≡ Γ(ψ --> η'γ)/Γ(ψ --> ηγ) and R ≡ Γ(ψ' --> ψ π)/Γ(ψ' --> ψη) is achieved in the context of a simple π-η-gh' mixing model. An η-η' mixing angle θ ⋍ - 19.5° and a large tadpole effect for the ηπ and η'π isospinviolating transitions are required. Both requirements are in agreement with recent data for the η-meson.