Eur. Phys. J. A (2007) 31: 527-533
https://doi.org/10.1140/epja/i2006-10185-6

QNP 2006

Aspects of strangeness -1 meson-baryon scattering

¹ Departamento de Fısica, Universidad de Murcia, E-30071, Murcia, Spain
² CAFPE and Departamento de Fısica Teórica y del Cosmos, Universidad de Granada, Campus de Fuente Nueva, E-18002, Granada, Spain

^* e-mail: oller@um.es

Received: 25 October 2006
Accepted: 1 November 2006
Published online: 22 February 2007

Abstract

We consider meson-baryon interactions in S-wave with strangeness -1. This is a sector populated by plenty of resonances interacting in several two-body coupled channels. We consider a large set of experimental data, where the recent experiments are remarkably accurate. This requires a sound theoretical description to account for all the data and we employ Unitary Chiral Perturbation Theory up to and including O(p ²). The spectroscopy of our solutions is studied within this approach, discussing the rise of the two Λ(1405)-resonances and of the Λ(1670), Λ(1800), Σ(1480), Σ(1620) and Σ(1750). We finally argue about our preferred fit.