Theoretical study of triaxial shapes of neutron-rich Mo and Ru nuclei

C. L. Zhang (张春莉), G. H. Bhat, W. Nazarewicz, J. A. Sheikh, and Yue Shi (石跃)
Phys. Rev. C 92, 034307 – Published 10 September 2015

Abstract

Background: Whether atomic nuclei can possess triaxial shapes at their ground states is still a subject of ongoing debate. According to theory, good prospects for low-spin triaxiality are in the neutron-rich Mo-Ru region. Recently, transition quadrupole moments in rotational bands of even-mass neutron-rich isotopes of molybdenum and ruthenium nuclei have been measured. The new data have provided a challenge for theoretical descriptions invoking stable triaxial deformations.

Purpose: To understand experimental data on rotational bands in the neutron-rich Mo-Ru region, we carried out theoretical analysis of moments of inertia, shapes, and transition quadrupole moments of neutron-rich even-even nuclei around Ru110 using self-consistent mean-field and shell model techniques.

Methods: To describe yrast structures in Mo and Ru isotopes, we use nuclear density functional theory (DFT) with the optimized energy density functional UNEDF0. We also apply triaxial projected shell model (TPSM) to describe yrast and positive-parity, near-yrast band structures.

Results: Our self-consistent DFT calculations predict triaxial ground-state deformations in Mo106,108 and Ru108,110,112 and reproduce the observed low-frequency behavior of moments of inertia. As the rotational frequency increases, a negative-γ structure, associated with the aligned ν(h11/2)2 pair, becomes energetically favored. The computed transition quadrupole moments vary with angular momentum, which reflects deformation changes with rotation; those variations are consistent with experiment. The TPSM calculations explain the observed band structures assuming stable triaxial shapes.

Conclusions: The structure of neutron-rich even-even nuclei around Ru110 is consistent with triaxial shape deformations. Our DFT and TPSM frameworks provide a consistent and complementary description of experimental data.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
5 More
  • Received 16 July 2015

DOI:https://doi.org/10.1103/PhysRevC.92.034307

©2015 American Physical Society

Authors & Affiliations

C. L. Zhang (张春莉)1,2, G. H. Bhat3, W. Nazarewicz1,4,5, J. A. Sheikh3, and Yue Shi (石跃)1

  • 1Department of Physics and Astronomy and NSCL/FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
  • 2State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
  • 3Department of Physics, University of Kashmir, Srinagar, 190 006, India
  • 4Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6373, USA
  • 5Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Pasteura 5, PL-02-093 Warsaw, Poland

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 92, Iss. 3 — September 2015

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review C

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×