Reexamination and extension of the liquid drop model: Correlation between liquid drop parameters and curvature term

The relationship between the volume and the surface energy coefficients in the liquid drop A −1/3 expansion of nuclear masses is discussed. The volume and surface coefficients share the same physical origin and their physical connection is used to extend the expansion with a curvature term. A possible generalization of the Wigner term is also suggested. This connection between coefficients is used to fit the experimental nuclear masses. The excellent fit obtained with a smaller number of parameters validates the assumed physical connections and the usefulness of the curvature term.