Nuclear deformation effect on the binding energies in heavy ions

Nuclear deformation effects on the binding energies in heavy ions are investigated. Approximate formulas for the nuclear-size correction and the isotope shift for deformed nuclei are derived. Combined with direct numerical evaluations, these formulas are employed to reanalyze experimental data on the nuclear-charge-distribution parameters in ²³⁸U and to revise the nuclear-size corrections to the binding energies in H- and Li-like ²³⁸U. As a result, the theoretical uncertainties for the ground-state Lamb shift in ²³⁸U⁹¹⁺ and for the 2p1/2-2s transition energy in ²³⁸U⁸⁹⁺ are significantly reduced. The isotope shift of the 2pⱼ-2s transition energies for ¹⁴²Nd⁵⁷⁺ and ¹⁵⁰Nd⁵⁷⁺ is also evaluated including nuclear size and nuclear recoil effects within a full QED treatment.