Island of rare Earth nuclei with tetrahedral and octahedral symmetries: possible experimental evidence.
Calculations using realistic mean-field methods suggest the existence of nuclear shapes with tetrahedral Td and/or octahedral Oh symmetries sometimes at only a few hundreds of keV above the ground states in some rare earth nuclei around 156Gd and 160Yb. The underlying single-particle spectra manifest exotic fourfold rather than Kramers's twofold degeneracies. The associated shell gaps are very strong, leading to a new form of shape coexistence in many rare earth nuclei. We present possible experimental evidence of the new symmetries based on the published experimental results--although an unambiguous confirmation will require dedicated experiments.
Dudek
J
J
Institut Pluridisciplinaire Hubert Curien IN2P3-CNRS/Université Louis Pasteur, F-67037 Strasbourg Cedex 2, France.
Curien
D
D
Dubray
N
N
Dobaczewski
J
J
Pangon
V
V
Olbratowski
P
P
Schunck
N
N