π−pBackward Elastic Scattering from 2.38 to 3.00 GeV/c

This paper presents differential cross sections for backward ${\pi }^{-}p$ elastic scattering in the angular region $-0.55\mathrm{}\ge {cos\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\ge -0.98\mathrm{}$ for five incident momenta: 2.38, 2.50, 2.65, 2.80, and 3.00 GeV/c. The structure of the angular distribution undergoes a marked change over this momentum interval. A pronounced dip near 180°, which is seen for momenta ≲2.50 GeV/c, becomes a sharp peak at 2.80 and 3.00 GeV/c. A minimum in the cross section at ${cos\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\simeq -0.7\mathrm{}$ is indicated at all momenta. In addition, a dip in the differential cross section appears at ${cos\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\simeq -0.92\mathrm{}$ at 3.00 GeV/c. A good fit to the data from 2.1 to 3.0 GeV/c is obtained with a direct-channel resonance model.