CHIRAL DYNAMICS OF LOW-ENERGY KAON-BARYON INTERACTIONS WITH EXPLICIT RESONANCE

The processes involving low-energy (K) over bar N and Y pi interaction s (where Y=Sigma or Lambda) are studied in the framework of heavy bary on chiral perturbation theory with the Lambda(1405) resonance appearin g as an independent field. The leading and next-to-leading terms in th e chiral expansion are taken into account. We show that an approach wh ich explicitly includes the Lambda(1405) resonance as an elementary qu antum field gives reasonable descriptions of both the threshold branch ing ratios and the energy dependence of total cross sections.