The negative parity states and some electromagnetic transition properties of even-odd erbium isotopes (${}^{159,161,163,165}\mathrm{Er}$) were studied within the framework of the interacting boson-fermion model. The single fermion is assumed to be in one of the ${\mathit{lh}}_{9/2},3p_{3/2},2f_{5/2}$, and $3p_{1/2}$ single-particle orbits. It was found that the calculated negative parity state energy spectra of the even-odd erbium isotopes agree quite well with the experimental data. The $B(E2)$ values were also calculated and compared with the experimental data.

• Received 22 September 2006

DOI:https://doi.org/10.1103/PhysRevC.75.034309