Three-body hadronic structure of low-lying $1/2^+$ $\Sigma$ and $\Lambda$ resonances

Understand

We discuss the dynamical generation of some low-lying $1/2^+$ $\Sigma$'s and $\Lambda$'s in two-meson one-baryon systems.

• These systems have been constructed by adding a pion in $S$-wave to the $\bar{K} N$ pair and its coupled channels, where the $1/2^-$ $\Lambda$(1405)-resonance gets dynamically generated.
• We solve Faddeev equations in the coupled-channel approach to calculate the $T$-matrix for these systems as a function of the total energy and the invariant mass of one of the meson-baryon pairs.
• This squared $T$-matrix shows peaks at the energies very close to the masses of the strangeness -1, $1/2^+$ resonances listed in the particle data book.