Shell-model-like approach based on cranking covariant density functional theory: Band crossing and shape evolution in Fe60

Abstract

The shell-model-like approach is implemented to treat the cranking many-body Hamiltonian based on the covariant density functional theory including pairing correlations with exact particle number conservation. The self-consistency is achieved by iterating the single-particle occupation probabilities back to the densities and currents. As an example, the rotational structures observed in the neutron-rich nucleus 60 Fe are investigated and analyzed. Without introducing any ad hoc parameters, the bandheads, the rotational spectra, and the relations between the angular momentum and rotational frequency for the positive parity band A, and negative parity bands B and C are well reproduced. The essential role of the pairing correlations is revealed. It is found that for band A, the bandcrossing is due to the change of the last two occupied neutrons from the 1f 5/2 signature partners to the 1g 9/2 signature partners. For the two negative parity signature partner bands B and C, the bandcrossings are due to the pseudo-crossing between the 1f 7/2, 5/2 and the 1f 5/2, 1/2 orbitals. Generally speaking, the deformation parameters β for bands A, B, and C decrease with rotational frequency. For band A, the deformation jumps from β ∼ 0.19 to β ∼ 0.29 around the bandcrossing. In comparison with its signature partner band C, band B exhibits appreciable triaxial deformation.

Rotational excitations in rare-earth nuclei: a comparative study within three cranking models with different mean fields and the treatments of pairing correlations

“…( 16), q 2 (ξ) and q 2 (η) are the diagonal elements of the stretched quadrupole operator. It turns out that reasonable agreement with experiment is obtained in cranking CDFT-SLAP with only monopole pairing [27]; recent investigation of Ref. [115] has shown that with renormalized pairing strengths the cranking CDFT-SLAP results with monopole pairing are quite similar to those obtained with the separable pairing force of Ref.…”

“…can be represented by any mean field Hamiltonian. So far the SLAPs based on phenomenological Nilsson [28] and Woods-Saxon [91] potentials and non-relativistic (Skyrme Hartree-Fock approach [92]) and relativistic (CDFT [27]) DFTs have been developed. In the present work, we employ two SLAPs: one is based on microscopic cranked CDFT approach and another on phenomenological cranked Nilsson Hamiltonian.…”

“…P iµ = 1 if |µ is occupied in MPC |i , and P iµ = 0 otherwise. Note that in the cranking CDFT-SLAP, the occupation probabilities will be iterated back into the densities and currents in Table II to achieve selfconsistency [27,88].…”

“…(ii) The cranking covariant density functional theory with pairing correlations treated by the shell-modellike approach (further abbreviated as cranking CDFT-SLAP [27]).…”

Systematic investigation of the high- K isomers and the high-spin rotational bands in the neutron-rich Nd and Sm isotopes by a particle-number conserving method

“…The PNC scheme has also been used both in relativistic and non-relativistic mean field models [43][44][45] and the total-Routhian-surface method with the Woods-Saxon potential [46,47]. Recently, the PNC method based on the cranking covariant density functional theory has been developed [48]. Similar approaches to treat pairing correlations with exactly conserved particle number can be found in Refs.…”