Kansuke Ninomiya

Duality aspects of meson--baryon scattering and urbaryon rearrangement amplitudes

On the basis of the urbaryon rearrangement pictures, differential cross section and polarization of forward and backward twobody scattering are studied phenomenologically. It is shown in the forward region that the observed large polarization and the break-ing of line reversal relation in differential cross sections are due to the existence of one of the Z-type urbaryon rearrangement amplitudes (Z/sub 2/) which has non-exotic SU(3) quantum number in all channels. In the backward region, a result is obtained that th Z/sub 2/ amplitude is suppressed remarkably compared with other urbaryon rearrangement amplitudes. Furthermore relative magnitude and phases among various urbaryon rearrangement amplitudes are obtained. Meanings of these results are discussed in connection with other theoretical frameworks, e.g., the absence rule, the duality, the Regge pole model and the SU (3) approaches. (auth)