Vibrational motion in nuclei

Problems relating to the understanding of the connection between collective and independent particle motions in the nucleus are discussed. The role played by the one particle field generated by collective distortion in the average nuclear density is examined. Examples of possibilities for vibrational modes in nuclei and problems associated with the interaction of the excitation quanta among themselves and with other elementary modes of excitation are presented. Included are discussions of shape oscillations, isovector models, spin-dependent models, and pairing modes. (6 figures) (U.S.)