Time delayed KN reactions and exotic baryon resonances

Evidences and hints, both from the theoretical and experimental side, of exotic baryon resonances with B = S, have been with us for the last thirty years. The poor status of the general acceptance of these Z resonances is partly due to the prejudice against penta-quark baryons and partly due to the opinion that a proof of the existence of exotic states must be rigorous. This can refer to the quality and amount of data gathered, and also to the analytical methods applied in the study of these resonances. It seems then mandatory that all possibilities and aspects be exploited. We do that by analyzing the time delay in KN scattering, encountering clear signals of the exotic Z resonances close to the pole values found in partial wave analyses.