The Small Angle Scattering of 970 MeV Protons by Carbon

The differential cross section for the scattering of 970 MeV protons by carbon through laboratory angles of 1½° to 5° has been measured using nuclear emulsions to detect the scattered particles. The results show a sharp rise at small angles due to the onset of Coulomb scattering and have been fitted at the larger angles (greater than 2°) in terms of a simple model in which the nucleus is represented by a purely imaginary central potential. Values for the diffraction and total cross sections are then derived. Preliminary results of a more detailed analysis, which includes a spin-orbit potential, shows that a fit can be obtained at all angles if a small negative real part to the central potential is included. Further evidence is found for polarization effects at these energies.