Quadrupole collectivity beyond N = 28: intermediate-energy Coulomb excitation of (47,48)Ar.
We report on the first experimental study of quadrupole collectivity in the very neutron-rich nuclei (47,48)Ar using intermediate-energy Coulomb excitation. These nuclei are located along the path from doubly magic Ca to collective S and Si isotopes, a critical region of shell evolution and structural change. The deduced B(E2) transition strengths are confronted with large-scale shell-model calculations in the sdpf shell using the state-of-the-art SDPF-Uand EPQQM effective interactions. The comparison between experiment and theory indicates that a shell-model description of Ar isotopes around N=28 remains a challenge.
National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
R
R
Winkler
A
A
Gade
T
T
Baugher
D
D
Bazin
B A
BA
Brown
T
T
Glasmacher
G F
GF
Grinyer
R
R
Meharchand
S
S
McDaniel
A
A
Ratkiewicz
D
D
Weisshaar