2 v 3 1 7 D ec 1 99 7 Chiral anomaly and η − η ′ mixing ∗

We determine the η−η mixing angle via a procedure relatively independent of theoretical assumptions by simultaneously fitting η, η reactions involving the anomaly— η, η → γγ, π+π−γ. We extract reasonably precise renormalized values of the octet and singlet pseudoscalar decay constants F8, F0, as well as the mixing angle θ. * Research supported in part by the National Science Foundation