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Title: Shell model and mean-field description of band termination in the A{approx}44 nuclei

Abstract

We study nuclear high-spin states undergoing the transition to the fully stretched configuration with maximum angular momentum I{sub max} within the space of valence nucleons. To this end, we perform a systematic theoretical analysis of non-fully-stretched I{sub max}-2 and I{sub max}-1 f{sub 7/2}{sup n} seniority isomers and d{sub 3/2}{sup -1}f{sub 7/2}{sup n+1} intruder states in the A{approx}44 nuclei from the lower-fp shell. We employ two theoretical approaches: (i) the density functional theory based on the cranked self-consistent Skyrme-Hartree-Fock method, and (ii) the nuclear shell model in the full sdfp configuration space allowing for 1p-1h cross-shell excitations. We emphasize the importance of restoration of broken angular momentum symmetry inherently obscuring the mean-field treatment of high-spin states. Overall good agreement with experimental data is obtained.

Authors:
;  [1];  [1];  [2];  [1];  [2];  [2];  [3]
  1. Institute of Theoretical Physics, University of Warsaw, ul. Hoza 69, 00-681 Warsaw (Poland)
  2. (United States)
  3. Lawrence Livermore National Laboratory, P.O. Box 808, L-414, Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
20995268
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.054306; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ANGULAR MOMENTUM; CONFIGURATION; CRANKING MODEL; DENSITY FUNCTIONAL METHOD; HARTREE-FOCK METHOD; HIGH SPIN STATES; ISOMERS; MASS NUMBER; MEAN-FIELD THEORY; NUCLEONS; SHELL MODELS; SKYRME POTENTIAL

Citation Formats

Zalewski, M., Zdunczuk, H., Satula, W., Joint Institute for Heavy Ion Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Nazarewicz, W., Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, and Stoitcheva, G.. Shell model and mean-field description of band termination in the A{approx}44 nuclei. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.054306.
Zalewski, M., Zdunczuk, H., Satula, W., Joint Institute for Heavy Ion Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Nazarewicz, W., Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, & Stoitcheva, G.. Shell model and mean-field description of band termination in the A{approx}44 nuclei. United States. doi:10.1103/PHYSREVC.75.054306.
Zalewski, M., Zdunczuk, H., Satula, W., Joint Institute for Heavy Ion Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Nazarewicz, W., Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, and Stoitcheva, G.. Tue . "Shell model and mean-field description of band termination in the A{approx}44 nuclei". United States. doi:10.1103/PHYSREVC.75.054306.
@article{osti_20995268,
title = {Shell model and mean-field description of band termination in the A{approx}44 nuclei},
author = {Zalewski, M. and Zdunczuk, H. and Satula, W. and Joint Institute for Heavy Ion Research, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 and Nazarewicz, W. and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 and Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 and Stoitcheva, G.},
abstractNote = {We study nuclear high-spin states undergoing the transition to the fully stretched configuration with maximum angular momentum I{sub max} within the space of valence nucleons. To this end, we perform a systematic theoretical analysis of non-fully-stretched I{sub max}-2 and I{sub max}-1 f{sub 7/2}{sup n} seniority isomers and d{sub 3/2}{sup -1}f{sub 7/2}{sup n+1} intruder states in the A{approx}44 nuclei from the lower-fp shell. We employ two theoretical approaches: (i) the density functional theory based on the cranked self-consistent Skyrme-Hartree-Fock method, and (ii) the nuclear shell model in the full sdfp configuration space allowing for 1p-1h cross-shell excitations. We emphasize the importance of restoration of broken angular momentum symmetry inherently obscuring the mean-field treatment of high-spin states. Overall good agreement with experimental data is obtained.},
doi = {10.1103/PHYSREVC.75.054306},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • We study nuclear high-spin states undergoing the transition to the fully stretched configuration with maximum angular momentum I{sub max} within the space of valence nucleons. To this end, we perform a systematic theoretical analysis of non-fully-stretched I{sub max}-2 and I{sub max}-1 f{sub 7/2}{sup n} seniority isomers and d{sub 3/2}{sup -1}f{sub 7/2}{sup n + 1} intruder states in the A{approx}44 nuclei from the lower-fp shell. We employ two theoretical approaches: (i) the density functional theory based on the cranked self-consistent Skyrme-Hartree-Fock method, and (ii) the nuclear shell model in the full sdfp configuration space allowing for 1p-1h cross-shell excitations. We emphasizemore » the importance of restoration of broken angular momentum symmetry inherently obscuring the mean-field treatment of high-spin states. Overall good agreement with experimental data is obtained.« less
  • High-spin states in proton-rich A{approx}60 nuclei on and near the N=Z line have been studied in a series of experiments performed with Gammasphere and the Microball charged-particle detector array. These experiments have led to the identification of more than 40 deformed and superdeformed rotational bands in more than a dozen different Ni, Cu, and Zn isotopes. Because of the limited spin content of the single-particle configurations in these relatively light nuclei, many of these bands are observed to, or close to, their terminating states. Lifetime measurements for two sets of strongly coupled rotational bands in {sup 62}Zn have confirmed themore » predicted loss of collectivity associated with the phenomenon of smooth band termination. Superdeformed bands have been observed in {sup 60,61,62,65}Zn, firmly establishing an island of superdeformation for nuclei with particle numbers N,Z{approx_equal}30. Linking transitions connecting the doubly-magic SD band in the N=Z nucleus {sup 60}Zn to the yrast line have been identified. These linking transitions not only provide the first definite spin, parity, and excitation energy measurements for SD states in the A{approx}60 mass region, but their stretched E2 character and relatively large B(E2) values suggest that the decay-out process in this region differs substantially from that observed in heavier systems. (c) 1999 American Institute of Physics.« less
  • High-spin states in the proton-rich nuclei {sup 62}Zn and {sup 60}Zn have been studied with Gammasphere and the Microball charged-particle detector array. Two sets of strongly coupled rotational bands in {sup 62}Zn have been observed up to the terminating states of their respective configurations and lifetime measurements for these bands confirm the predicted loss of collectivity associated with the smooth termination of rotational bands. Superdeformed (SD) bands have been observed in both {sup 62}Zn and {sup 60}Zn, establishing a new region of superdeformation for nuclei with particle numbers N,Z{approx_equal}30. Linking transitions connecting the doubly-magic SD band in {sup 60}Zn tomore » the yrast line have been identified. These linking transitions not only provide the first spin, parity, and excitation energy measurements for SD states in the A{approx}60 mass region, but their stretched E2 character and relatively large B(E2) values and intensities suggest that the decay-out process for A{approx}60 SD bands differs substantially from that observed in heavier systems.« less
  • A shell-correction method is applied to nuclei far from the beta stability line, and its suitability to describe effects of the particle continuum is discussed. The sensitivity of predicted locations of one- and two-particle drip lines to details of the macroscopic-microscopic model is analyzed.
  • Two-shell-model interactions are constructed in the model space of the five proton and six neutron orbits just above the double shell closure at {sup 132}Sn. One interaction uses the two-body matrix elements calculated by Kuo and Herling for use near {sup 208}Pb. For the other, the proton-proton two-body matrix elements are replaced with effective ones of Kruse and Wildenthal and selected proton-neutron matrix elements were varied in order to better reproduce the known energy spectra of {sup 134}Sb. The main difficulty in this construction is the determination of the neutron single-particle energies. This determination was done by comparison of theoreticalmore » and experimental ({ital d},{ital p}) spectroscopic factors for the {ital N}=83, {ital Z}=54, 56, and 58 isotones. The {Delta}{ital J}{ne}0 first-forbidden {beta}{sup {minus}} decays of {sup 133}Sn(7/2{sup {minus}}), {sup 134}Sn(0{sup +}), {sup 134}Sb(0{sup {minus}}), and {sup 134}Sb(7{sup {minus}}) were considered in order to exemplify the application of these interactions.« less