Pole Models forS-Wave Hyperon Decay

The $K^{*}$-pole model and the baryon-pole model are considered as alternatives to the current-algebra calculation of $s$-wave hyperon decay amplitudes. The conditions under which all three of them yield identical results are clarified. A simple dynamical model, based on the ${K_1}^0$ spurion at zero four-momentum, leads to a combination of $K^{*}$-pole and baryon-pole terms which satisfy these conditions.