Coupled-channel study of gamma p -> K+ Lambda

A coupled-channel (CC) approach has been developed to investigate kaon phot oproduction 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. Cal culations for the gammap --> K+ Lambda reaction have been performed, and co mpared with the recent data from SAPHIR, with emphasis on the CC effects. W e show that the CC effects are significant at the level of inducing 20% cha nges on total cross sections; thereby, demonstrating the need to include pi N channels to correctly describe the gammap --> K+ Lambda reaction. (C) 200 1 Published by Elsevier Science B.V.