Dependence of the r.m.s. nuclear radius on the deformation parameters

Abstract

The concept of "nuclear compressibility under deformation", introduced by Fradkin and others in their experimental studies of isotope shifts, is analyzed. It is shown that in the harmonic-oscillator model Fradkin's compressibility parameter ξ can occur in a natural way. Theoretical estimates of ξ are obtained, using spherical and deformed oscillator models, as ξ = −5/4π and −5/16π respectively. They bracket the experimental value [Formula: see text]. Possible improvements of these estimates are discussed.