The theory of an electron interacting with a quantized liquid drop is examined, the Hamiltonian being consistently written to second order in the parameters describing the distortion. When second-order terms are kept, some care is necessary in defining the observable value of the radius. Form factors, calculated in Born approximation, for all of the transitions in the drop model are given, as well as the probabilities for real photon emission. The correction to Coulomb scattering coming from the exchange of a transverse photon is also calculated. A model is made of the contribution of the nuclear magnetization to the transverse photon exchange. In general, the Coulomb scattering will dominate. Spherically symmetric compressional oscillations of a drop with surface tension are also discussed and the form factors for transitions are calculated.

• Received 14 September 1961

DOI:https://doi.org/10.1103/PhysRev.126.653