Photoproduction ofKMesons in Hydrogen near Threshold

Abstract

The total cross sections near threshold of the three processes: $\ensuremath{\gamma}+p\ensuremath{\rightarrow}{\ensuremath{\Lambda}}^{0}+{K}^{+}, {\ensuremath{\Sigma}}^{0}+{K}^{+}, {\ensuremath{\Sigma}}^{+}+{K}^{0}$, have been calculated as a function of the incident photon energy in the laboratory system under the assumptions that the hyperons have spin ${\mathrm{\textonehalf{}}}^{+}$ with positive anomalous magnetic moments and that the $K$ meson has spin 0\ifmmode\pm\else\textpm\fi{} and is coupled to the baryon field by direct Yukawa interaction. A pseudoscalar $K$ meson gives a steep increase of the cross section for neutral production and at the same time gives a large $\frac{{K}^{0}}{{K}^{+}}$ production ratio compared to that for a scalar $K$ meson.