CARNEGIE MELLON UNIV,DEPT PHYS,PITTSBURGH,PA 15213
; ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA
In this paper, we present a calculation of the four isospin channels of the kaon photoproduction gamma N-->K Sigma in the framework of the chiral quark model. The relative strength and phases in each isospin channel are determined by the quark model wave function with SU(6)xO(3) symmetry. The duality hypothesis is imposed to limit the number of the t channel exchanges. The only free parameter, the coupling constant g(K Sigma N), is fitted to the total cross section data in gamma p-->K(+)Sigma(0) channel. We found a remarkable agreement with the data available in the other isospin channels, and it represents a dramatic improvement over the similar calculation in the traditional isobaric model.