Axial and pseudoscalar current correlators and their couplings to eta and etaprime mesons

TL;DR

This paper uses QCD sum rules to analyze axial current correlators and their couplings to eta and eta' mesons, providing consistent coupling values aligned with experimental data.

Contribution

It introduces a comprehensive QCD sum rule analysis of singlet and octet axial current correlators, including instanton and screening effects, to determine meson couplings.

Findings

Consistent values for f^8_eta, f^0_eta, f^8_etaprime, f^0_etaprime obtained.

Sum rules agree with phenomenological decay and production data.

Inclusion of instanton and screening effects enhances certain correlator analyses.

Abstract

Correlators of singlet and octet axial currents, as well as anomaly and pseudoscalar densities have been studied using QCD sum rules. Several of these sum rules are used to determine the couplings f^8_eta, f^0_eta, f^8_etaprime and f^0_etaprime. We find mutually consistent values which are also in agreement with phenomenological values obtained from data on various decay and production rates. While most of the sum rules studied by us are independent of the contributions of direct instantons and screening correction, the singlet-singlet current correlator and the anomaly-anomaly correlator improve by their inclusion.