Two-dimensional collective Hamiltonian for chiral and wobbling modes. II. Electromagnetic transitions

We calculate the intraband electromagnetic transitions in the framework of a collective Hamiltonian for chiral and wobbling modes. By going beyond the mean-field approximation on the orientations of the rotational axis, the collective Hamiltonian provides descriptions of both the yrast band and collective excitation bands. For a system with one $h_{11/2}$ proton particle and one $h_{11/2}$ neutron hole coupled to a triaxial rotor ($\gamma =-{30}^{\circ }$), the intraband electromagnetic transitions given by the one-dimensional and two-dimensional collective Hamiltonian are compared with results obtained by using the tilted axis cranking approach and the particle rotor model. Compared with the tilted axis cranking approach, the electromagnetic transitions given by the collective Hamiltonian agree better with the transitions obtained by using the particle rotor model because quantum fluctuations are considered.

Figure 1

The intraband $M1$ and $E2$ transition probabilities of the doublet bands obtained by the 1DCH in comparison with the TAC [(a), (c), (e)] and the PRM [(b), (d), (f)] as functions of spin.

Figure 2

The effective azimuth angles ${\phi }^{\mathrm{eff}}$ of in the doublet bands obtained by the 1DCH as functions of spin in comparison with the azimuth angle $\phi$ by the TAC.

Figure 3

The intraband $M1$ and $E2$ transition probabilities of the lowest bands in the groups ($++$), ($+-$), ($-+$), and ($--$) obtained by the 2DCH in comparison with the TAC [(a), (c), (e)] and the PRM [(b), (d), (f)].

Figure 4

The effective tilted cranking angles ${\phi }^{\mathrm{eff}}$ and ${\theta }^{\mathrm{eff}}$ of the lowest states in the groups ($++$), ($+-$), ($-+$), and ($--$) as functions of spin obtained by the 2DCH in comparison with the tilted cranking angles $\phi$ and $\theta$ by the TAC.