The description of the elastic scattering of particles by atomic nuclei in terms of the optical model is studied. It is shown that the optical model does not represent only an approximation to the many-body problem, although the optical model potential must in general be considered to contain spin-orbit couplings. An explicit expression is obtained for the optical model potential in terms of the amplitudes for scattering of the incident particle by the individual neutrons and protons of the nucleus. The potential also depends upon correlations in the positions of the nuclear particles. A calculation of the parameters of the optical model seems to be in good agreement with some meson scattering experiments.

• Received 1 June 1953

DOI:https://doi.org/10.1103/PhysRev.92.291