Nuclear deformation in the A≈100 region: Comparison between new masses and mean-field predictions

New precision masses of ¹⁰⁰⁻¹⁰²Sr and ¹⁰⁰⁻¹⁰²Rb, including first direct masses for those strontium and rubidium isotopes, used to test whether deformation continues in the A≈100 region.

ISOLTRAP Penning-trap measurements at ISOLDE, compared with mean-field and beyond-mean-field calculations, plus Hartree-Fock-Bogoliubov work for even and odd isotopes.

The data show the deformed region persists at least to N=65. That tells models whether krypton is the low-Z edge of the A≈100 island of deformation, which later krypton proposals then targeted.