Measurements of the Polarization inπ±pElastic Scattering at 5.15 GeV/c

We report results obtained at the zero-gradient synchrotron for the polarization in ${\pi }^{+}p$ and ${\pi }^{-}p$ elastic scattering at 5.15 GeV/c, from $-t=0.2\mathrm{}\mathrm{to}2.0$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The results may be qualitatively understood on the basis of a simple Regge-pole model. In addition to the flip amplitude due to $\rho$ exchange, a significant $I=0\mathrm{}$ flip amplitude is required.