The nature of the Λ (1405) is discussed based on the unitarised coupled-channels approach with chiral dynamics (chiral unitary model). This approach describes the over(K, ̄) N scattering cross sections and the Λ (1405) spectra phenomenologically very well. With this successful description of Λ (1405), it is found that the Λ (1405) is composed by two resonance states having different coupling nature to the meson-baryon states. As a consequence, the resonance position in the πΣ invariant mass spectrum depends on the initial channel of the Λ (1405) production. To observe the Λ (1405) initiated by the over(K, ̄) N channel, K- d → Λ (1405) n is one of the most favorable reactions. Hadronic molecule states with kaons are also discussed by emphasizing an important role of Λ (1405) as a quasibound state of over(K, ̄) N.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics