Parity doublet bands in Th223 within reflection-asymmetric triaxial particle rotor model

Abstract

The recently updated parity doublet structures in $^{223}\mathrm{Th}$ are investigated by using the reflection-asymmetric triaxial particle rotor model. The calculated results well reproduce the available data of the energy spectra and the $B(E1)/B(E2)$ ratios for both medium spin region and the newly established higher spin region, as well as the average value of $B(M1)/B(E2)$ for spins $9/2\ensuremath{\hbar}$ and $11/2\ensuremath{\hbar}$ in the positive-parity band. The main components of the intrinsic wave functions are analyzed to investigate the intrinsic wave functions and their evolutions with spin. The parity doublet bands are mainly based on a single neutron configuration, in which the largest component of the intrinsic wave function is $\ensuremath{\nu}({g}_{9/2},{j}_{15/2})[\mathrm{\ensuremath{\Omega}}=5/2]$ and the second largest one is $\ensuremath{\nu}({g}_{9/2},{j}_{15/2})[\mathrm{\ensuremath{\Omega}}=3/2]$. The amplitude of the largest component decreases whereas the second largest one increases with increasing spin, and the signature splitting behavior for the parity doublet bands could be understood by the variation of these main components with spin.