A particle-core Hamiltonian is used to describe the lowest parity partner bands, $K^{\pi }=1/2^{\pm }$, in ${}^{219}\mathrm{Ra}$, ${}^{237}\mathrm{U}$, and ${}^{239}\mathrm{Pu}$ and three pairs of parity partner bands, $K^{\pi }=1/2^{\pm },3/2^{\pm },$ and $5/2^{\pm }$, in ${}^{227}\mathrm{Ra}$. The core is described by a quadrupole and octupole boson Hamiltonian. The particle-core Hamiltonian consists of four terms: a quadrupole-quadrupole, an octupole-octupole, a spin-spin, and a rotational ${\widehat{I}}^2$ interaction, with $\widehat{I}$ denoting the total angular momentum. The model Hamiltonian is treated within a projected spherical particle-core basis. The calculated excitation energies are compared with the corresponding experimental data as well as with those obtained using other approaches. For ${}^{219}\mathrm{Ra}$, we also calculated the $E1$ and $E2$ branching ratios. Also, we searched for some signatures for static octupole deformation in the considered odd isotopes.

• Received 21 April 2009

DOI:https://doi.org/10.1103/PhysRevC.80.044327