Nearly degenerate partner bands observed in A ∼ 130 odd-odd triaxial nuclei are interpreted as a manifestation of chirality in the intrinsic reference frame. A phenomenological approach, based on a core-particle-hole coupling model, has been developed to address the experimental observables. This laboratory-frame model, in which chiral symmetry has been restored, includes a triaxial core, a particle/hole single-particle Hamiltonian, and quadrupole-quadrupole interactions. The optimal model parameters are investigated. The results of the calculations indicate the existence of pairs of πh11/2ν-1h11/2 states with the same spin, parity, and similar excitation energy forming partner bands that are nearly degenerate over a range of spins. These calculated partner bands are consistent with the chiral band interpretation and are in agreement with experimental observations in this region. This model has been applied to excited states in 132La, which have been studied via the 123Sb(13C,4n) reaction using γ-ray spectroscopic techniques. In addition to the yrast πh11/2ν-1h11/2 band, the partner band was observed with experimental properties consistent with the same πh11/2ν-1h11/2 configuration. These doublet bands resemble those observed systematically for several N = 75 isotones of 132La.
|Number of pages||3989537|
|Journal||Physical Review C - Nuclear Physics|
|Publication status||Published - 2002 Apr|
ASJC Scopus subject areas
- Nuclear and High Energy Physics