Photoproduction ofΛ(1405)andΣ0(1385)on the proton atEγ=1.5−2.4GeV

Differential cross sections for $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}\ensuremath{\Lambda}(1405)$ and $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\Sigma}}^{0}(1385)$ reactions have been measured in the photon energy range from 1.5 to 2.4 GeV and the angular range of $0.8l\mathrm{cos}(\ensuremath{\Theta})l1.0$ for the ${K}^{+}$ scattering angle in the center-of-mass system. This data is the first measurement of the $\ensuremath{\Lambda}(1405)$ photoproduction cross section. The line shapes of $\ensuremath{\Lambda}(1405)$ measured in ${\ensuremath{\Sigma}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\Sigma}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ decay modes were different with each other, indicating a strong interference of the isospin 0 and 1 terms of the $\ensuremath{\Sigma}\ensuremath{\pi}$ scattering amplitudes. The ratios of $\ensuremath{\Lambda}(1405)$ production to ${\ensuremath{\Sigma}}^{0}(1385)$ production were measured in two photon energy ranges: near the production threshold ($1.5l{E}_{\ensuremath{\gamma}}l2.0$ GeV) and far from it ($2.0l{E}_{\ensuremath{\gamma}}l2.4$ GeV). The observed ratio decreased in the higher photon energy region, which may suggest different production mechanisms and internal structures for these hyperon resonances.