Strange dibaryon resonance in the K̄NN-πYN system

Three-body resonances in the K̄NN system have been studied within a framework of the K̄NN-πYN coupled-channel Faddeev equation. By solving the three-body equation, the energy dependence of the resonant K̄N 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 K̄N interaction is constructed from the leading order term of the chiral Lagrangian using relativistic kinematics. The Λ(1405) resonance is dynamically generated in this model, where the K̄N 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~79 MeV and width Γ~74 MeV. The energy of the three-body resonance is found to be sensitive to the model of the I=0 K̄N interaction.