ELASTIC-DIFFERENTIAL CROSS SECTION OF $pi$$sup +$ + p AT 1.5, 2.0, AND 2.5 Bev/c

Elastic-scattering angular distributions are measured for rature of the d /sup +/ + p scattering at 1.5, 2.0, and 2.5 Bev/c, using spark chambers to detect scattered pions and protons. A bump that decreases in amplitude with increasing momentum is observed in the backward hemisphere in the 1.5- and 2.0Bev/ c distributions, but is not observed in the 2.5-Bev/c distributions. It appears reasonable to attribute this phenomenon to the 1.46-Bev/c resonance observed in the rature of the d /sup +/ + p total cross section. The data are compared with rature of the d /sup -/ + p data and are found to support the theoretical prediction that the scattering cross sections for both charge states should become equal at high energies. The angular distributions are fit with a power series in cos F * and the extrapolated values for the scattering cross section in the backward direction are compared with the calculation of the neutronexchange pole contribution to the cross section. The elementary'' neutron-pole term contribution is calculated to be 90 mb/sr at 2.0 Bev/c, in violent disagreement with the extrapolated value, sup 14/ recover 0.5 mb/sr. (auth)