2022

Geldhof, S.; Kortelainen, M.; Beliuskina, O.; Campbell, P.; Caceres, L.; Cañete, L.; Cheal, B.; Chrysalidis, K.; Devlin, C. S.; de Groote, R. P.; de Roubin, A.; Eronen, T.; Ge, Z.; Gins, W.; Koszorus, A.; Kujanpää, S.; Nesterenko, D.; Ortiz-Cortes, A.; Pohjalainen, I.; Moore, I. D.; Raggio, A.; Reponen, M.; Romero, J.; Sommer, F.

The impact of nuclear deformation can been seen in the systematics of nuclear charge radii, with radii generally expanding with increasing deformation. In this Letter, we present a detailed analysis of the precise relationship between nuclear quadrupole deformation and the nuclear size. Our approach combines the first measurements of the changes in the mean-square charge radii of well-deformed palladium isotopes between A=98 and A=118 with nuclear density functional calculations using Fayans functionals, specifically Fy(std) and Fy(Δr,HFB), and the UNEDF2 functional. The changes in mean-square charge radii are extracted from collinear laser spectroscopy measurements on the 4d95s 3D3→4d95p3P2 atomic transition. The analysis of the Fayans functional calculations reveals a clear link between a good reproduction of the charge radii for the neutron-rich Pd isotopes and the overestimated odd-even staggering: Both aspects can be attributed to the strength of the pairing correlations in the particular functional which we employ.