Particle-number-conserving analysis of multiquasiparticle bands in ^(177)Lu

The experimental one-, three-, and five-quasiparticle bands in 177Lu are analyzed by the particle-number conserving （PNC） method for treating the cranked shell model with pairing interaction, in which the blocking effects are taken into account exactly. The experimental moments of inertia are reproduced very well by PNC calculations with us free parameter.

Effects of Rotation, Blocking and Octupole Deformation on Pairing Correlations in the U and Pu Isotopes

including octupole correlations in the Nilsson potential,the ground-state rotational bands in the reflection-asymmetric(RA)nuclei are investigated by using the cranked shell model(CSM)with the monopole and quadrupole pairing correlations treated by a particle-number-conserving(PNC)method.The experimental kinematic moments ofinertia(Mols)for alternating-parity bands in the even-even nuclei ^(236,238)U and ^(238,240)Pu,as well as paritydoublet bands in the odd-A nuclei 237U and 239Pu are reproduced well by the PNC-CSM calculations.The higher J(1)for the intrinsic s=-i bands in ^(237)U and ^(239)Pu,compared with the s=+1 bands in the neighboring even-even nuclei ^(236,238)U and ^(238,240)Pu,can be attributed to the pairing gap reduction due to the Pauli blocking effect.The gradual increase of J(i)versus rotational frequency can be explained by the pairing gap reduction due to the rotation.The Mols of reflection-asymmetric nuclei are higher than those of reflection-symmetric(RS)nuclei at low rotational frequency.Moreover,the inclusion of a larger octupole deformation 8,in the RA nuclei results in more significant pairing gap reduction compared with the RS nuclei.

Multi-quasiparticle rotational bands in neutron-rich erbium isotopes

Multi-quasiparticle states and rotational bands in neutron-rich erbium isotopes have been investigated by the configuration- constrained pairing-deformation-frequency self-consistent total-Routhian-surface （TRS） method with particle-number-conserved pairing. Specifically, the recently observed Kπ = 4- bands in 168,170,172Er have been found to experience a configuration change in our calculation. Some other multi-quasiparticle states with uncertain configuration assignments have been reinvestigated by calculating their collective rotations. The configuration-constrained TRS calculation can reproduce experimental data consistently.

Difference in moments of inertia and paring interaction strength in superdeformed nuclei

The difference in the bandhead moments of inertia between the superdeformed (SD) band 194Hg(1) and the two-quasiparticle SD bands 194Hg(2,3) was investigated using the particle-number-conserving treatment for the cranked shell model Hamiltonian, and the pairing interaction strength in SD nuclei is estimated to be much weaker than that in normally deformed nuclei.

Theoretical investigation of the antimagnetic rotation in ^(104)Pd

The particle-number-conserving method based on the cranked shell model is used to investigate the antimagnetic rotation band in ^(104) Pd. The experimental moments of inertia and reduced B(E2) transition probabilities are reproduced well. The J^((2))/B(E2) ratios are also discussed. The occupation probability of each orbital close to the Fermi surface and the contribution of each major shell to the total angular momentum alignment as function of rotational frequency are analyzed. The backbending mechanism of the ground state band in ^(104) Pd is understood clearly and the configuration of the antimagnetic rotation after backbending is clarified. In addition, the crossing of a four quasiparticle state with this antimagnetic rotation band is also predicted. By examining the closing of the angular momenta of four proton holes towards the neutron angular momentum, the "two-shears-like" mechanism for this antimagnetic rotation is investigated and two stages of antimagnetic rotation in ^(104) Pd are clearly seen.

Signature splitting of the πh_(11/2) band and high-spin structures in ^(155)Tb

Seven experimentally observed bands of 155Tb are analyzed in detail,using the particle-number-conserving method for treating the cranked shell model with monopole and quadrupole pairing interactions.We satisfactorily reproduce the experimental alignments and especially focus on the microscopic mechanism of the second back-bending and the influence of pair interaction on ultrahigh spins.Our calculated results show that the πi13/2 orbitals are too high to give a contribution to the moment of inertia below ω≈ 0.7 MeV.Instead,the crossing between the π[541]1/2 and other proton orbitals is responsible for the second back-bending.We assign a possible configuration to the decoupled band found in 155Tb and predict eleven bands which are experimentally unobserved.

Nonadditivity in moments of inertia of high-K multiquasiparticle bands

The experimental high-K 2- and 3-quasiparticle bands of well deformed rare-earth nuclei are analyzed. It is found that there exists significant nonadditivity in moments of inertia （MOIs） for these bands. The microscopic mechanism of the rotational bands is investigated by the particle number conserving （PNC） method in the frame of cranked shell model with pairing, in which the blocking effects are taken care of exactly. The experimental rotational frequency dependence of these bands is well reproduced in PNC calculations. The nonadditivity in MOIs originates from the destructive interference between Pauli blocking effects.