  The meson-baryon interaction in s-wave in the strangeness S=-1 sector has
been studied, employing a chiral SU(3) Lagrangian up to next-to-leading order
(NLO) and implementing unitarization in coupled channels. The parameters of the
Lagrangian have been fitted to a large set of experimental data in different
two-body channels, paying special attention to the $\bar{K} N \rightarrow K
\Xi$ reaction, which is particularly sensitive to the NLO terms. With the aim
of improving the model in the $K\Xi$ production channels, effects of the high
spin hyperon resonances $\Sigma(2030)$ and $\Sigma(2250)$ have been taken into
account phenomenologically.
