Coupled channel Faddeev calculations of a K-bar Nπ quasibound state

The K-bar Nπ system is studied using separable interactions fitted to data available on the s-wave K-bar N-πY subsystem and the p-wave πN, πY, ππ and πK-bar subsystems. Three-body K-bar Nπ-πYπ coupled channel Faddeev equations with relativistic kinematics are solved in search for poles in the complex energy plane. A K-bar Nπ quasibound pole with quantum numbers I(JP)=1(3/2-) is found near and below the K-bar Nπ threshold, its precise location depending sensitively on the poorly known shape of the p-wave πY interaction. This K-bar Nπ quasibound state suggests the existence of a D13Σ resonance with width about 60 MeV near threshold (M∼1570 MeV), excluding meson absorption contributions.