Coupled-channel study of γp→K+ Λ

A coupled-channel (CC) approach has been developed to investigate kaon photoproduction on the nucleon. In addition to direct K+ Lambda production, our CC approach accounts for strangeness production including K+ Lambda final state interactions with both pi (0) p and pi (+) n intermediate states. Calculations for the gammap --> K+ Lambda reaction have been performed, and compared with the recent data from SAPHIR, with emphasis on the CC effects. We show that the CC effects are significant at the level of inducing 20% changes on total cross sections; thereby, demonstrating the need to include piN channels to correctly describe the gammap --> K+ Lambda reaction. (C) 2001 Published by Elsevier Science B.V.