KAON PHOTOPRODUCTION NEAR-THRESHOLD AND THEIR COUPLING-CONSTANTS

The kaon photoproduction is investigated at the threshold energy. We d iscuss (i) the difference between the pseudoscalar (PS) and the pseudo vector (PV) coupling descriptions on the KNY interaction, (ii) the con tributions of t-channel poles of vector and axial vector mesons, and ( iii) the contributions of nucleon and hyperon resonances to the E(0)() amplitude. We suggest that total cross sections near threshold can b e used to estimate the leading coupling constant, g(KN Lambda) and to make clear which description is the better of PS and PV coupling schem es for this reaction from future experiments.