Authors
Ayangeakaa, A. D.; Janssens, R.; Zhu, S.; Allmond, J.; Brown, B. A.; Wu, C.; Albers, M.; Auranen, K.; Bucher, B.; Carpenter, M. P.; Kondev, F. G.; Lauritsen, T.; Li, J.; Seweryniak, D.; Stolze, S.; Wu, J.
Abstract
The deformation properties of the low-lying states in 76Ge have been investigated following a safe-energy Coulomb excitation measurement with the GRETINA tracking array and CHICO2 heavy-ion counter at the ATLAS accelerator facility at Argonne National Laboratory. A comprehensive set of transition and static E2 matrix elements were extracted from the measured differential Coulomb cross sections and compared with results of configuration-interaction shell-model calculations and computations carried out within the framework of the generalized triaxial rotor model. The remarkable agreement between the calculated and experimental data supports a near-maximum triaxial deformation for the ground state of 76Ge. In addition, the degree of softness of the asymmetry in 76Ge and 76Se was investigated using rotational invariants generated from configuration-interaction shell-model wave functions computed with the jj44b and JUN45 effective interactions. The resulting invariants are shown to be consistent with a stiff triaxial deformation in 76Ge and a predominantly soft triaxial potential for 76Se, in agreement with the conclusions of recent works by this collaboration.