Measurement of the Polarization Parameter in Backwardπ+pElastic Scattering at 1.60, 1.80, 2.11, and 2.31GeVc

Measurements of polarization in ${\pi }^{+}p$ elastic scattering have been made at 1.60, 1.80, 2.11, and 2.31 $\frac{\mathrm{GeV}}{c}$. The data cover the entire angular range, with emphasis on the backward region. Comparisons have been made with both $u$-channel and $t$-channel models, as well as with predictions of phase-shift analyses. While the agreement is generally poor in all cases, the best agreement is with some $t$-channel predictions.