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W. Nazarewicz

Publications and source records attributed to W. Nazarewicz.

210 records · Page 12Linked to original sources
arXiv1996

Shell Structure of the Superheavy Elements

Ground state properties of the superheavy elements (SHE) with Z from 108 to 128 and N from 150 to 192 are investigated using both the Skyrme-Hartree-Fock method with a density-independent contact pairing interaction and the macroscopic-microscopic approach with an average Woods-Saxon potential and a monopole pairing interaction. Detailed analysis of binding energies, separation energies, shell effects, single proton and neutron states, equilibrium deformations, alpha-decay energies, and other observables is given.

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arXiv1996

Additivity of Quadrupole Moments in Superdeformed Bands: Single-Particle Motion at Extreme Conditions

Quadrupole and hexadecapole moments of superdeformed bands in the $A$$\sim$150 mass region have been analyzed in the cranking Skyrme-Hartree-Fock model. It is demonstrated that, independently of the intrinsic configuration and of the proton and neutron numbers, the charge moments calculated with respect to the doubly-magic superdeformed core of $^{152}$Dy can be expressed very precisely in terms of independent contributions from the individual hole and particle orbitals. This result, together with earlier studies of the moments of inertia distributions, suggests that many features of the superdeformed bands in the $A$$\sim$150 mass region can be very well understood in terms of an almost undisturbed single-particle motion.

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arXiv1995

Mean-field description of ground-state properties of drip-line nuclei: Pairing and continuum effects

Ground-state properties of exotic even-even nuclei with extreme neutron-to-proton ratios are described in the framework of the self-consistent mean-field theory with pairing formulated in coordinate space. This theory properly accounts for the influence of the particle continuum, which is particularly important for weakly bound systems. The pairing properties of nuclei far from stability are studied with several interactions emphasizing different aspects, such as the range and density dependence of the effective interaction. Measurable consequences of spatially extended pairing fields are presented, and the sensitivity of the theoretical predictions to model details is discussed.

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arXiv1995

GCM study of hexadecapole correlations in superdeformed $^{194}$Hg

The role of hexadecapole correlations in the lowest superdeformed band of $^{194}$Hg is studied by self consistent mean field methods. The generator coordinate method with particle number projection has been applied using Hartree-Fock wave functions defined along three different hexadecapole paths. In all cases, the ground state is not significantly affected by hexadecapole correlations and the energies of the corresponding first excited hexadecapole vibrational states lie high in energy. The effect of rotation is investigated with the Skyrme-Hartree-Fock-Bogolyubov method and a zero range density-dependent pairing interaction.

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arXiv1994

Closed shells at drip-line nuclei

The shell structure of magic nuclei far from stability is discussed in terms of the self-consistent spherical Hartree-Fock-Bogoliubov theory. In particular, the sensitivity of the shell-gap sizes and the two-neutron separation energies to the choice of particle-hole and particle-particle components of the effective interaction is investigated.

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arXiv1994

Octupole Correlations in Excited Bands of Superdeformed Dy-152

RPA calculations, based on the cranked shell model, are performed for superdeformed \dy\ in which five excited bands have been found recently. We show that characteristic features of the observed dynamical moments of inertia are well accounted for by explicitly taking the octupole correlations into account. Importance of the interplay between rotation and octupole vibrations is stressed, and it is suggested that one of the observed excited bands might be a collective octupole vibration built on the superdeformed yrast band.

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arXiv1994

The Delta I=4 Bifurcation in Superdeformed Bands

The origin of the Delta I=4 staggering effect which has recently been observed in several superdeformed bands is discussed. The Hamamoto and Mottelson model, which is based on a phenomenological parametrization of the hamiltonian as a quartic function of angular momentum, is analyzed. A stability of the description with respect to the C_4 - symmetry breaking terms is studied.

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arXiv1994

Hexadecapole Interaction and the Delta I=4 Staggering Effect in Rotational Bands

A role of the multipole interaction in the description of the $\triangle I$=4 staggering phenomenon is investigated in a model consisting of a single-$j$ shell filled by identical nucleons. Exact diagonalization of the quadrupole-plus-hexadecapole Hamiltonian shows that the hexadecapole-hexadecapole interaction can produce a $\triangle I$=4 periodicity in the yrast sequence.

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arXiv1993

Low-energy M1 and E3 excitations in the proton-rich Kr-Zr region

Low-energy intrinsic $K^π$=1$^+$, $0^-$, $1^-$, $2^-$, and $3^-$ states in the even-even proton-rich Sr, Kr, and Zr nuclei are investigated using the quasiparticle random phase approximation. In the Z$\simeq$N nuclei the lowest-lying 1$^+$ states are found to carry unusually large $B(M1)$ strength. It is demonstrated that, unlike in the heavier nuclei, the octupole collectivity in the light zirconium region is small and, thus, is not directly correlated with the systematics of the lowest negative parity states.

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arXiv1993

Approximate Particle Number Projection for Rotating Nuclei

Pairing correlations in rotating nuclei are discussed within the Lipkin-Nogami method. The accuracy of the method is tested for the Krumlinde-Szymański R(5) model. The results of calculations are compared with those obtained from the standard mean field theory and particle-number projection method, and with exact solutions.

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