Evidence for a Dibaryon Signal in the Measurement of Elasticπ+−dpolScattering

The vector analyzing power ($i{T}_{11}$) in elastic $\pi -d_{\mathrm{pol}}$ scattering has been measured for several angles at $T_{\pi }=142\mathrm{} \mathrm{and} 256$ MeV. The results are compared with calculations reported in the literature. At the lower energies, Faddeev calculations agree fairly well with the data. At the higher energies, the experimental results differ markedly from any conventional calculation, but agree surprisingly well with predictions in which effects of dibaryon resonances are explicitly included.