The nature of Lambda(1405) hyperon resonance in chiral dynamics

Understand

The nature of the Lambda(1405) is discussed based on the unitarised coupled-channels approach with chiral dynamics (chiral unitary model).

• This approach describes the Kbar N scattering cross sections and the Lambda(1405) spectra phenomenologically very well.
• With this successful description of Lambda(1405), it is found that the Lambda(1405) is composed by two resonance states having different coupling nature to the meson-baryon states.
• As a consequence, the resonance position in the pi Sigma invariant mass spectrum depends on the initial channel of the Lambda(1405) production.