Nature of excited 𝚵 baryons with threshold effects

Abstract

Spectroscopy of excited baryons with strangeness S = −2 is stimulated by recent experimental developments. Here we focus on the Ξ(1620) which locates close to the K̅Λ threshold. To take into account the threshold effects, we construct the coupled-channels meson-baryon scattering amplitude where the Ξ(1620) appears as a resonance. We demonstrate that the K̅Λ threshold effects distort the peak of the Ξ(1620) resonance from the simple Breit-Wigner distribution.