A study of $\eta K \bar K$ and $\eta' K \bar K$ with the fixed center approximation to Faddeev equations

Abstract

In the present work we investigate the three-body systems of $\eta K \bar K$ and $\eta' K \bar K$, by taking the fixed center approximation to Faddeev equations. We find a clear and stable resonance structure around 1490 MeV in the squared $\eta K \bar K$ scattering amplitude, which is not sensitive to the renormalization parameters. Conversely, we get only an enhancement effect of the threshold in the $\eta' K \bar K$ amplitude that indicates the difficulty to bind the $\eta' K \bar K$ system as a consequence of a weaker $\eta' K$ interaction than the $\eta K$ one. We associate the $\eta K \bar K$ state found to the $\eta(1475)$.