Chiral Anomaly and Eta-Eta' Mixing

Abstract

We determine the $η-η'$ mixing angle via a procedure relatively independent of theoretical assumptions by simultaneously fitting $η- eta'$ reactions involving the anomaly--$η,η'\toγγ, π^+π^-γ$. We extract reasonably precise renormalized values of the octet and singlet pseudoscalar decay constants $F_8,F_0$ as well as the mixing angle $θ$.