Eur. Phys. J. A (2006) 28: 63-82
https://doi.org/10.1140/epja/i2006-10011-3

Hadron Physics

On the strangeness -1 S-wave meson-baryon scattering

Departamento de Fısica, Universidad de Murcia, E-30071, Murcia, Spain

Received: 17 March 2006
Accepted: 11 April 2006
Published online: 10 May 2006

Abstract

We consider meson-baryon interactions in S-wave with strangeness -1. This is a non-perturbative sector populated by plenty of resonances interacting in several two-body coupled channels. We study this sector combining a large set of experimental data. The recent experiments are remarkably accurate demanding a sound theoretical description to account for all the data. We employ unitary chiral perturbation theory up to and including O(p ²) to accomplish this aim. The spectroscopy of our solutions is studied within this approach, discussing the rise from the pole content of the two Λ(1405) resonances and of the Λ(1670), Λ(1800), Σ(1480), Σ(1620) and Σ(1750) ones. We finally argue about our preferred solution.