J. Y. Zeng

Microscopic mechanism of identical superdeformed bands in 1 9 2 , 1 9 3 , 1 9 4 Hg

The microscopic mechanism of identical superdeformed bands in

Nuclear pairing reduction due to rotation and blocking

{}^{192,193,194}\mathrm{Hg}

Particle-number conserving analysis for the systematics of high-K pair-broken bands in Hf and Lu isotopes (170{<=}A{<=}178)

is investigated using the particle-number conserving treatment for the cranked shell model with monopole and quadrupole pairing interactions. In combination with the analysis for normally deformed identical bands in the rare-earth nuclei, it is shown that the identical bands observed in normally deformed rare-earth nuclei and superdeformed nuclei in the

Nonadiabatic Berry phase of a two-state system and nonstationarity of quantum states

A\ensuremath{\sim}190

Criteria of the spin assignment of rotational band

region result from the competition among shell effect, pairing interaction, blocking effect on pairing, and Coriolis antipairing interaction, where a strict and consistent treatment of blocking effect plays a crucial role.

Identical Superdeformed Bands and Quantized Spin Alignments in A ~ 190 Region*

Nuclear pairing gaps of normally deformed and superdeformed nuclei are investigated using the particle-number-conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly. Both rotational frequency omega dependence and seniority (number of unpaired particles) nu dependence of the pairing gap (Delta) over tilde are investigated. For the ground-state bands of even-even nuclei, PNC calculations show that, in general, (Delta) over tilde decreases with increasing omega, but the omega dependence is much weaker than that calculated by the number-projected Hartree-Fock-Bogolyubov approach. For the multiquasiparticle bands (seniority nu > 2), the pairing gaps stay almost omega independent. As a function of the seniority nu, the bandhead pairing gaps (Delta) over tilde(nu, omega = 0) decrease slowly with increasing nu. Even for the highest seniority nu bands identified so far, (Delta) over tilde(nu, omega = 0) remains greater than 70% of (Delta) over tilde(nu = 0, omega = 0).

Giant halo at the neutron drip line in Ca isotopes in relativistic continuum Hartree-Bogoliubov theory

Within the framework of the particle-number conserving (PNC) formalism, one-quasiparticle and low-lying high-K pair-broken (multiquasiparticle) bands systematically observed in Hf and Lu isotopes (170{<=}A{<=}178) are analyzed consistently. The PNC method deals with the cranked shell model with pairing interaction, in which the Pauli blocking effects are exactly accounted for, and the pairing interaction strength is determined by the experimental odd-even difference in binding energies. With an appropriate Nilsson level scheme that best fits the experimental bandhead energies of the one-quasiparticle bands, the experimental moments of inertia (MOIs) of these one-quasiparticle and multiquasiparticle bands (including configuration and frequency dependences, signature splitting, etc.) can be well reproduced without any additional free parameter. In most cases, the PNC formalism supports the configuration assignments in earlier works. the PNC calculation also reveals that the experimental systematics of low-lying high-K pair-broken bands in Hf and Lu isotopes are intimately related to the subshell effects near the Fermi surfaces of both protons and neutrons.

Reduction of nuclear moment of inertia due to pairing interaction

The nonadiabatic Berry phases in the magnetic resonance under various initial conditions are investigated and compared with the adiabatic Berry phase. The general formalism for calculating the nonadiabatic Berry phase of a two-state system in terms of the expansion of instantaneous energy eigenstates is presented. Some numerical calculations and discussions are made. The Berry phase of a two-statesystem under an impulsive interaction is addressed.

Spin determination and quantized alignment in the superdeformed bands in sup 152 Dy, sup 151 Tb, and sup 150 Gd

Based on the very general properties of the rotational band of axially symmetric nucleus, some rules of the I variation of the kinematic and dynamic moments of inertia are obtained, which may serve as the effective criteria of the spin assignment of rotational band. Extensive analysis of large amount of rotational bands (below bandcrossing) of normally deformed even-even nuclei whose spins were established shows that these rules do hold without exception. The spins of the yrast superdeformed bands of even-even nuclei in the actinide region (fission isomeric bands), and in the , 150 regions are analyzed also. The spin of the lowest observed level of the yrast superdeformed band in is determined to be , rather than or 24.

BLOCKING EFFECT AND ODD-EVEN DIFFERENCES IN THE MOMENTS OF INERTIA OF RARE-EARTH NUCLEI

Identical superdeformed bands exist extensively in the A ~ 190 region. With a few exceptions, almost all the superdeformed bands observed have their identical counterparts, supporting the concept of the quantized spin alignment. A likely explanation of the systematics of the superdeformed bands within the framework of particle-rotor model with pseudo-spin symmetry is presented.