Pseudospin symmetry and octupole correlations for multiple chiral doublets in 131Ba

Abstract

A Reflection-Asymmetric Triaxial Particle Rotor Model (RAT-PRM) with three quasiparticles and a reflection-asymmetric triaxial rotor is developed, and applied to investigate the observed multiple chiral doublets (MχD) candidates with octupole correlations in 131 Ba, i.e., two pairs of positive-parity bands D3-D4 and D5-D6, as well as one pair of negative-parity bands D7-D8. The energy spectra, the energy staggering parameters, the B(M 1)/B(E2) ratios, and the B(E1)/B(E2) ratios are reproduced well. The chiral geometries for these MχD candidates are examined by the azimuthal plots, and the evolution of chiral geometry with spin is clearly demonstrated. The intrinsic structure for the positive-parity bands is analyzed and the possible pseudospin-chiral quartet bands are suggested.