  Using a unitary extension of chiral perturbation theory with a lowest-order
s-wave SU(3) chiral Lagrangian we study low-energy meson-baryon scattering in
the strangeness $S=-2$ sector. A scattering-matrix pole is found around 1606
MeV which corresponds to an s-wave $\Xi$ resonance with $J^P=1/2^-$. We
identify this resonance with the $\Xi(1620)$ state, quoted in the Particle Data
Book with $I=1/2$ but with unknown spin and parity. The addition of the $S=-2$
state to the recently computed $\Lambda(1670)$, $\Sigma(1620)$ and N(1535)
states completes the octet of $J^P=1/2^-$ resonances dynamically generated in
this chiral unitary approach.
