Behavior of the collective rotor in nuclear chiral motion

The behavior of the collective rotor in the chiral motion of triaxially deformed nuclei is investigated using the particle rotor model by transforming the wave functions from the $K$ representation to the $R$ representation. The energy spectra of the doublet bands and their energy differences as functions of the triaxial deformation are first examined and then the angular momentum components of the rotor, proton, neutron, and the total system are investigated. Moreover, the probability distributions of the rotor angular momentum ($R$ plots) and their projections onto the three principal axes ($K_R$ plots) are analyzed. The evolution of the chiral mode from a chiral vibration at the low spins to a chiral rotation at high spins is illustrated at triaxial deformations $\gamma ={20}^{\circ }$ and ${30}^{\circ }$.

Figure 1

(a) Energy spectra of the yrast and yrare bands for the $\pi \left(1h_{11/2}\right)\otimes \nu {\left(1h_{11/2}\right)}^{-1}$ configuration calculated in the PRM as a function of triaxial deformation parameter $\gamma$. (b) Energy differences between the yrare and yrast bands as a function of $\gamma$.

Figure 2

Root mean square values of angular momentum components along the intermediate ($i$), short ($s$), and long ($l$) axes of the rotor, proton, neutron, and the total spin for the yrast and yrare bands calculated in the PRM at $\gamma =0^{\circ }, {10}^{\circ }, {20}^{\circ }$, and ${30}^{\circ }$.

Figure 3

$R$ plots, probability distributions of the rotor angular momentum in the yrast and yrare bands for the $\pi \left(1h_{11/2}\right)\otimes \nu {\left(1h_{11/2}\right)}^{-1}$ configuration calculated with the PRM at $\gamma =0^{\circ }, {10}^{\circ }, {20}^{\circ }$, and ${30}^{\circ }$.

Figure 4

$K_{R_l}$ plots, probability distributions for the projection of the rotor angular momentum onto the $l$ axis in the yrast and yrare bands for the $\pi \left(1h_{11/2}\right)\otimes \nu {\left(1h_{11/2}\right)}^{-1}$ configuration calculated with the PRM at $\gamma =0^{\circ }, {10}^{\circ }, {20}^{\circ }$, and ${30}^{\circ }$.

Figure 5

Same as Fig. 4, but for the projection onto the $s$ axis.

Figure 6

Same as Fig. 4, but for the projection onto the $i$ axis.