Elasticπ+−pandp−pScattering at 1.23 Bev/c

Abstract

Elastic ${\pi }^{+}-p$ scattering at 1.1 Bev and elastic $p-p$ scattering at 582 Mev have been measured using a propane bubble chamber. On the basis of 661 identified ${\pi }^{+}-p$ elastic scatterings found in the scanning of 1.726×${10}^6$ cm of pion track, the total elastic cross section is found to be 12.3±1.2 mb. The differential cross section is rather isotropic at large angles and exhibits a strong peak for small forward scattering angles. If the forward peak is interpreted as diffraction scattering according to the optical model, the data are best fitted by a proton with a ${\pi }^{+}-p$ interaction radius, $R=\left({{0.99}_{-0.11\mathrm{}}}^{+0.13\mathrm{}}\right)\times {10}^{-13\mathrm{}}$ cm and an opacity, $O={{0.70}_{-0.07\mathrm{}}}^{+0.06\mathrm{}}$.