Measurements of the Asymmetries in the Differential Cross Sections for $\overline{p}p\to \overline{p}p$ and $\overline{p}p\to {\pi }^{-}{\pi }^{+}$ Using Polarized Protons

We report measured asymmetries as a function of polar scattering angle for the reactions $\overline{p}p\to {\pi }^{-}{\pi }^{+}$ and $\overline{p}p\to \overline{p}p$, using a polarized proton target. The annihilation data, obtained at a $\overline{p}$ momentum of 1.64 GeV/c, are the first asymmetry data to be collected for this channel. A fit of these data and published differential cross section data is made by a partial-wave expansion, and the results are compared with a previous analysis. The elastic scattering data, obtained at 1.64 and 2.55 GeV/c, are fitted with an eight-parameter strong-absorption model.