Systematic Survey of theα−αInteraction

A systematic survey of the subject of the $\alpha -\alpha$ interaction is made. The early observations of $\alpha$ emission and resulting theoretical descriptions, especially the $\alpha$-particle model of nuclei, are described, as are more recent $\alpha -\alpha$ scattering experiments. The latter were designed to obtain information about the nature of the $\alpha -\alpha$ interaction and about the energy levels of ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ by studying the resonance behavior of the phase shifts. The phenomenological approach, i.e., the attempt to construct the $\alpha -\alpha$ potential which reproduces the experimental phase shifts, is described as are detailed theoretical constructions of the repulsive inner part and attactive outer part of the $\alpha -\alpha$ interaction. Studies of how the $\alpha -\alpha$ interaction provides better understanding of the structure of $\alpha$-clustered nuclei and also of the fundamental forces between the constituents of these nuclei are discussed. Suggestions for the direction of further efforts are made.