Electromagnetic transitions in multiple chiral doublet bands

Abstract

Multiple chiral doublet bands (M$\ddot{I}‡$D) in the $80$, 130 and $190$ mass regions are studied by the model of ${\hat{I}}^3$=90${}^{\circ }$ triaxial rotor coupled with identical symmetric proton-neutron configurations. By selecting the suitable basis, the calculated wave functions are explicitly exhibited to be symmetric under the operator $\hat{A}$, which is defined as rotation by $90^{\circ }$ about 3-axis with the exchange of valance proton and neutron. We found that both $M1$ and $E2$ transitions are allowed between the levels with different values of $A$, while are forbidden between the levels with same values of $A$. Such a selection rule holds true for M$\ddot{I}‡$D in different mass regions.

16 pages, 3 figures in Chinese Physics C 2016