π−pElastic Scattering Near 180° at 8 and 16 GeV/c

Abstract

We report differential cross sections for ${\pi }^{-}p$ elastic scattering near 180° at incident pion momenta of 8 and 16 GeV/c. For $\mathrm{}\left|u\right|<0.5\mathrm{}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ the formula $\frac{d\sigma }{\mathrm{du}}=A\exp \mathrm{}\left(\mathrm{Bu}\right)\mathrm{}$ fits the data very well. At 8 GeV/c, $A=3.75\mathrm{}\pm 0.35$ μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and $B=3.16\mathrm{}\pm 0.24$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-2\mathrm{}}$. At 16 GeV/c, $A=0.91\mathrm{}\pm 0.13$ μb/${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ and $B=4.23\mathrm{}\pm 0.40$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-2\mathrm{}}$. A Reggepole model fit to these data gives for the ${\Delta }_{\delta }$ trajectory $\alpha \mathrm{}\left(u\right)=(-0.06\mathrm{}\pm 0.12)+(0.8\pm 0.3)u$.