Strange dibaryon resonance in the K-NN-πY N system

Three-body resonances in the (K) over bar NN system have been studied within a framework of the (K) over bar NN-pi YN coupled-channel Faddeev equation. By solving the three-body equation, the energy dependence of the resonant (K) over barN amplitude is fully taken into account. The S-matrix pole has been investigated from the eigenvalue of the kernel with the analytic continuation of the scattering amplitude on the unphysical Riemann sheet. The (K) over barN interaction is constructed from the leading order term of the chiral Lagrangian using relativistic kinematics. The Lambda(1405) resonance is dynamically generated in this model, where the (K) over barN interaction parameters are fitted to the data of scattering length. As a result we find a three-body resonance of the strange dibaryon system with binding energy B similar to 79 MeV and width Gamma similar to 74 MeV. The energy of the three-body resonance is found to be sensitive to the model of the I = 0 (K) over barN interaction.