Abstract :
In order to study the ΣN spin-orbit interaction, asymmetries of the polarized Σ+ elastic scattering on proton has been measured. The polarized Σ+ hyperons were produced through the p(π+,K+)Σ+ reaction in a liquid-scintillator active target, and tracks of Σ+p scattering events were recorded with a newly-developed track detector named SCITIC (scintillating track image camera). Analyses of data from an early stage of experiment indicated a large Σ+p spin-orbit interaction in contrast to the case of the small ΔN spin-orbit interaction.