First exploration of wobbling modes in an isotone chain: The <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>59</mml:mn></mml:mrow></mml:math> case
H. M. Dai, Q. B. Chen, Xian-Rong Zhou
Abstract
The possible existence of wobbling modes in the $N=59$ isotones $^{95}\mathrm{Kr}, ^{97}\mathrm{Sr}, ^{99}\mathrm{Zr}, ^{101}\mathrm{Mo}, ^{103}\mathrm{Ru}, ^{105}\mathrm{Pd}$, and $^{107}\mathrm{Cd}$ is explored by the constrained triaxial covariant density functional theory combined with quantum particle rotor model calculations. It is found that there are several states with suitable triaxial deformations and high-$j$ particle configuration to establish wobbling modes in $^{97}\mathrm{Sr}, ^{99}\mathrm{Zr}, ^{101}\mathrm{Mo}, ^{103}\mathrm{Ru}$, and $^{105}\mathrm{Pd}$. The available experimental energy spectra based on the $\ensuremath{\nu}{(1{h}_{11/2})}^{1}$ configuration in $^{97}\mathrm{Sr}$ and $^{99}\mathrm{Zr}$ are described well. The decreased energy difference between the doublet bands, the enhanced $B{(E2)}_{\text{out}}/B{(E2)}_{\text{in}}$ values, as well as the one-phonon oscillation characteristic of the total angular momentum indicate that the two nuclei can be transverse wobbling candidates, which suggests the possibility of a larger region of wobbling modes near the $A\ensuremath{\approx}100$ mass region.