Study of the a0(980) meson via the radiative decay φ→ηπ0γwith the KLOE detector

摘要

We have studied the φ →a0(980)γ process with the KLOE detector at the Frascati φ-factory DA-NE by detecting the φ → ηπ0γ decays in the final states with η → γγ and η → π+π-π0. We havemeasured the branching ratios for both final states: Br(φ →ηπ0γ ) = (7.01 ± 0.10 ± 0.20) × 10-5 and (7.12 ± 0.13 ± 0.22) × 10-5, respectively. We have also extracted the a0(980) mass and its couplings to ηπ0, K+K-, and to the φ meson from the fit of the ηπ0 invariant mass distributions using different phenomenological models.