Magnetic rotations inBi202andBi203

Abstract

Four magnetic dipole bands in ${}^{202}\mathrm{Bi}$ and ${}^{203}\mathrm{Bi}$ are investigated by the systematic comparison with similar bands in Pb isotopes and the tilted axis cranking covariant density functional theory (TAC-CDFT) calculations. The spin and configuration are assigned by the comparison with magnetic rotational bands in Pb isotopes. The corresponding configurations are suggested to be $\pi h_{9/2}{i}_{13/2}{s}_{1/2}^{-1}\otimes \nu i_{13/2}^{-1}$, $\pi h_{9/2}{i}_{13/2}{s}_{1/2}^{-1}\otimes \nu i_{13/2}^{-2}{\left(fp\right)}^{-1}$, and $\pi h_{9/2}{i}_{13/2}{s}_{1/2}^{-1}\otimes \nu i_{13/2}^{-1}{\left(fp\right)}^{-1}$ for the four magnetic dipole bands. The calculated energy spectra and the relation between spin and rotational frequency with TAC-CDFT are in good agreement with available experimental data, further supporting the spin and configuration assignments. The deformation parameters, transition probabilities, and the angular momenta contributions of protons and neutrons are also studied. These calculated quantities, together with the experimental data and the similarity with Pb isotopes, confirm the shear mechanism of these four magnetic dipole bands in ${}^{202}\mathrm{Bi}$ and ${}^{203}\mathrm{Bi}$.