hyodo˙chiral07˙final2 Modern Physics Letters A c ○ World Scientific Publishing Company

We discuss several aspects of the Λ(1405) resonance in relation to the recent theoretical developments in chiral dynamics. We derive an effective single-channel K̄N interaction based on chiral SU(3) coupled-channel approach, emphasizing the important role of the πΣ channel and the structure of the Λ(1405) in K̄N phenomenology. In order to clarify the structure of the resonance, we study the behavior with the number of colors (Nc) of the poles associated with the Λ(1405), and argue the physical meaning of the renormalization procedure.