Hyperon-Proton Scattering Experiment and Recent Progress of Strangeness Nuclear Physics at J-PARC

High intensity secondary beam in J-PARC enables us to perform strangeness nuclear physics programs in order to investigate the baryon-baryon (BB) interactions between the octet baryons. As one of the experiments at the K1.8 beam line, a high statistics Sigma p scattering experiment has been performed. The differential cross sections of the Sigma(-) p elastic scattering for the momentum region from 470 to 850 MeV/c have been successfully measured with an improved accuracy. The statistical error of 10% level was achieved with a fine angular step of d cos theta = 0.1 by identifying the largest statistics of about 4500 Sigma(-) p elastic scattering events from 1.72 x 10(7) Sigma(-) particles. The differential cross sections show clear forward peaking structure and the forward and backward ratio is large particularly in the higher momentum regions. The accurate data will impose a strong constraint on the theoretical models of the BB interactions.