Dynamical generation of $J^P=3/2-$ resonances and the $Λ(1520)$ resonance

Abstract

The lowest order chiral Lagrangian is used to study s-wave interactions of the baryon decuplet with the octet of pseudoscalar mesons. The coupled channel Bethe Salpeter equation is used to obtain dynamically generated $\tfrac{3}{2}^-$ resonances in the partial wave amplitudes which provide a reasonable description to a number of 3 and 4-star resonances like $Δ(1700)$, $Λ(1520)$, $Σ(1670)$, $Σ(1940)$, $Ξ(1820)$, $Ω(2250)$ etc. The phenomenological introduction of d-wave channels in the coupled channel scheme along with the existing s-wave channels is shown to provide a much improved description of the $Λ(1520)$ resonance. The prediction of the absolute strength of the cross section in the reactions $K^-p\toΛπ^0π^0$ and $K^-p\toΛπ^+π^-$ provided by this scheme shows a good agreement with existing data.

Talk given at International Workshop on the Physics of Excited Baryons NSTAR05, 12-15 October 2005, Tallahassee, Florida, USA