Observations of a Backward Peak inπ−p→pρ−AT 8 AND 16 GeV/c

We report differential cross sections for ${\rho }^{-}$ production near 180° in the reaction ${\pi }^{-}p\to p{\rho }^{-}$ at 8 and 16 GeV/c. These cross sections, which cover a range of $\mathrm{}\left|u\right|\mathrm{}<~0.6$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, are well represented by the formula $\frac{d\sigma }{\mathrm{du}}=A\exp \mathrm{}\left(\mathrm{Bu}\right)\mathrm{}$ and are comparable in magnitude to backward ${\pi }^{-}p$ elastic cross sections. Results are compared to Regge model calculations.