Differential Cross Section And Photon-Beam Asymmetry For The (Gamma)Over-Right-Arrown -> K+Sigma(-) Reaction At E-Gamma=1.5-2.4 Gev

Differential cross sections and photon-beam asymmetries have been measured for the gamma n -> K+Sigma(-) and gamma p -> K+Sigma(0) reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of E-gamma=1.5-2.4 GeV at 0.6 < cos Theta(K)(cm)< 1. The cross section ratio of sigma(+)(K)Sigma(-)/sigma(+)(K)Sigma(0), expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+Sigma(-) reaction, large positive asymmetries are observed, indicating the dominance of K-* exchange. The large difference between the asymmetries for the K+Sigma(-) and K+Sigma(0) reactions cannot be explained by simple theoretical considerations based on Regge model calculations.