The inelastic scattering of nucleons, deuterons, and alpha particles from light nuclei is discussed in terms of direct interactions. The validity of this description, and of the approximations made here and by other authors in calculating cross sections, are analyzed in detail. Physical arguments are given for the use of a collective representation of light nuclei, in order to explain the preferential excitation of certain well-defined nuclear states by short-wavelength projectiles. As an example, the alpha-particle model is used to characterize ${\mathrm{Be}}^9$ and the inelastic cross sections for excitation of rotational, vibrational, and single-particle states are calculated with an impulse approximation. The model, and results computed from it, are examined and compared to experimental findings.

• Received 16 June 1958

DOI:https://doi.org/10.1103/PhysRev.112.2029