Proton-Proton Scattering at 340 Mev

Measurements of the proton-proton differential scattering cross section using 340-Mev protons show a cross section approximately constant between 41^∘{} and 90^∘{} in the center of mass system. Two methods of counting the scattered protons have been used. The first method uses a counter telescope to count the scattered protons. The second method utilizes coincidences between counters which record the two protons involved in a single scattering process. The first method gives slightly higher cross sections; the average value of the differential cross section is (5.5±{}1.0)×{}10^-27 cm² steradian^-1 in the center of mass system. Although the scattering appears isotropic it is larger than can be accounted for with pure S-scattering. There is a strong suggestion, but no positive proof, that n-p and p-p forces are different.The p-p scattering at high energy is even qualitatively different from n-p scattering at comparable energy. In the p-p scattering the presence of other than S-wave scattering is evidenced in the magnitude of the cross section but not in the angular dependence in the range 41^∘{} to 90^∘{} center of mass system.