Andrea Jungclaus | Searcharxiv

arXiv2025

Direct proton transfer on $^{46}$Ar supports the presence of a charge density bubble linked to a novel nuclear structure below $^{48}$Ca

The $^{46}$Ar($^3$He,d)$^{47}$K reaction was performed in inverse kinematics using a radioactive $^{46}$Ar beam produced by the SPIRAL1 facility at GANIL and a cryogenic $^{3}$He target. The AGATA-MUGAST-VAMOS setup allowed the coincident measurement of the $γ$ rays, deuterons and recoiling $^{47}$K isotopes produced by the reaction. The relative cross sections towards the proton-addition states in $^{47}$K point towards a depletion of the $πs_{1/2}$ shell. The experimental findings are in good agreement with ab initio calculations, which predict that $^{46}$Ar exhibits a charge density bubble associated with a pronounced proton closed-shell character.

nucl-ex↗

arXiv2008

On the origin of the anomalous behaviour of 2+ excitation energies in the neutron-rich Cd isotopes

Recent experimental results obtained using $β$ decay and isomer spectroscopy indicate an unusual behaviour of the energies of the first excited 2$^{+}$ states in neutron-rich Cd isotopes approaching the N=82 shell closure. To explain the unexpected trend, changes of the nuclear structure far-off stability have been suggested, namely a quenching of the N=82 shell gap already in $^{130}$Cd, only two proton holes away from doubly magic $^{132}$Sn. We study the behaviour of the 2$^+$ energies in the Cd isotopes from N=50 to N=82, i.e. across the entire span of a major neutron shell using modern beyond mean field techniques and the Gogny force. We demonstrate that the observed low 2$^+$ excitation energy in $^{128}$Cd close to the N=82 shell closure is a consequence of the doubly magic character of this nucleus for oblate deformation favoring thereby prolate configurations rather than spherical ones.

nucl-th↗