Analysis of the coupling constants ga0ηπ0 and ga0η'π0 with light-cone QCD sum rules

Abstract

In this article, we take the point of view that the light scalar meson a0(980) is a conventional qq state, and calculate the coupling constants ga0ηπ0 and ga0 η'π0 with the light-cone QCD sum rules. The central value of the coupling constant ga0ηπ0 is consistent with the one extracted from the radiative decay φ(1020) a0(980)γ η π0 γ. The central value and lower bound of the decay width a0 η π0=127+84-48 MeV are compatible with the experimental data of the total decay width a0(980)=(50-100) MeV from the Particle Data Group with very model dependent estimation (the decay width can be much larger), while the upper bound is too large. We give possible explanation for the discrepancy between the theoretical calculation and experimental data.