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Title: Landscape of pear-shaped even-even nuclei

Abstract

The phenomenon of reflection-asymmetric nuclear shapes is relevant to nuclear stability, nuclear spectroscopy, nuclear decays and fission, and the search for new physics beyond the standard model. Global surveys of ground-state octupole deformation, performed with a limited number of models, suggest that the number of pear-shaped isotopes is fairly limited across the nuclear landscape. Here, we carry out a global analysis of ground-state octupole deformations for particle-bound even-even nuclei with Z ≤ 110 and N ≤ 210 using nuclear density functional theory (DFT) with several nonrelativistic and covariant energy density functionals. In this way, we can identify the best candidates for reflection-asymmetric shapes. The calculations are performed in the frameworks of axial reflection-asymmetric Hartree-Fock-Bogoliubov theory and relativistic Hartree-Bogoliubov theory using DFT solvers employing harmonic oscillator basis expansion. We consider five Skyrme and four covariant energy density functionals. We predict several regions of ground-state octupole deformation. In addition to the “traditional” regions of neutron-deficient actinide nuclei around 224Ra and neutron-rich lanthanides around 146Ba, we identified vast regions of reflection-asymmetric shapes in very neutron-rich nuclei around 200Gd and 288Pu, as well as in several nuclei around 112Ba. Our analysis suggests several promising candidates with stable ground-state octupole deformation, primarily in the neutron-deficientmore » actinide region, that can be reached experimentally. Detailed comparison between Skyrme and covariant models is performed. Octupole shapes predicted in this study are consistent with the current experimental information. This work can serve as the starting point of a systematic search for parity doublets in odd-mass and odd-odd nuclei, which will be of interest in the context of new physics searches.« less

Authors:
ORCiD logo [1]; ORCiD logo [2];  [2]; ORCiD logo [1]; ORCiD logo [3]
  1. Michigan State University, East Lansing, MI (United States)
  2. Mississippi State University, Starkville, MS (United States)
  3. Université Libre de Bruxelles, Brussels (Belgium)
Publication Date:
Research Org.:
Mississippi State Univ., Starkville, MS (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP)
OSTI Identifier:
1669900
Grant/Contract Number:  
SC0013037; NA0003885; NA0002925; SC0015376; SC0013365
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 102; Journal Issue: 2; Journal ID: ISSN 2469-9985
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Collective levels; Nuclear binding; Nuclear density functional theory; Nuclear structure & decays; Rare & new isotopes

Citation Formats

Cao, Yuchen, Agbemava, S. E., Afanasjev, A. V., Nazarewicz, W., and Olsen, E.. Landscape of pear-shaped even-even nuclei. United States: N. p., 2020. Web. https://doi.org/10.1103/physrevc.102.024311.
Cao, Yuchen, Agbemava, S. E., Afanasjev, A. V., Nazarewicz, W., & Olsen, E.. Landscape of pear-shaped even-even nuclei. United States. https://doi.org/10.1103/physrevc.102.024311
Cao, Yuchen, Agbemava, S. E., Afanasjev, A. V., Nazarewicz, W., and Olsen, E.. Mon . "Landscape of pear-shaped even-even nuclei". United States. https://doi.org/10.1103/physrevc.102.024311. https://www.osti.gov/servlets/purl/1669900.
@article{osti_1669900,
title = {Landscape of pear-shaped even-even nuclei},
author = {Cao, Yuchen and Agbemava, S. E. and Afanasjev, A. V. and Nazarewicz, W. and Olsen, E.},
abstractNote = {The phenomenon of reflection-asymmetric nuclear shapes is relevant to nuclear stability, nuclear spectroscopy, nuclear decays and fission, and the search for new physics beyond the standard model. Global surveys of ground-state octupole deformation, performed with a limited number of models, suggest that the number of pear-shaped isotopes is fairly limited across the nuclear landscape. Here, we carry out a global analysis of ground-state octupole deformations for particle-bound even-even nuclei with Z ≤ 110 and N ≤ 210 using nuclear density functional theory (DFT) with several nonrelativistic and covariant energy density functionals. In this way, we can identify the best candidates for reflection-asymmetric shapes. The calculations are performed in the frameworks of axial reflection-asymmetric Hartree-Fock-Bogoliubov theory and relativistic Hartree-Bogoliubov theory using DFT solvers employing harmonic oscillator basis expansion. We consider five Skyrme and four covariant energy density functionals. We predict several regions of ground-state octupole deformation. In addition to the “traditional” regions of neutron-deficient actinide nuclei around 224Ra and neutron-rich lanthanides around 146Ba, we identified vast regions of reflection-asymmetric shapes in very neutron-rich nuclei around 200Gd and 288Pu, as well as in several nuclei around 112Ba. Our analysis suggests several promising candidates with stable ground-state octupole deformation, primarily in the neutron-deficient actinide region, that can be reached experimentally. Detailed comparison between Skyrme and covariant models is performed. Octupole shapes predicted in this study are consistent with the current experimental information. This work can serve as the starting point of a systematic search for parity doublets in odd-mass and odd-odd nuclei, which will be of interest in the context of new physics searches.},
doi = {10.1103/physrevc.102.024311},
journal = {Physical Review C},
number = 2,
volume = 102,
place = {United States},
year = {2020},
month = {8}
}

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Works referenced in this record:

Transition to deformed shapes as a nuclear Jahn-Teller effect
journal, May 1984


Microscopic origin of nuclear deformations
journal, July 1994


Spontaneous symmetry breaking in rotating nuclei
journal, June 2001


89. Remarks about pear-shaped nuclei
journal, January 1956


Stability of Pear-Shaped Nuclear Deformations
journal, November 1957


Nuclear octupole deformation and the mechanism of fission
journal, February 1961


Intrinsic reflection asymmetry in atomic nuclei
journal, April 1996


Octupole collectivity in nuclei
journal, June 2016


On the stable octupole deformation of nuclei
journal, October 1981


Analysis of octupole instability in medium-mass and heavy nuclei
journal, November 1984


Nuclear Ground-State Masses and Deformations
journal, March 1995

  • Moller, P.; Nix, J. R.; Myers, W. D.
  • Atomic Data and Nuclear Data Tables, Vol. 59, Issue 2, p. 185-381
  • DOI: 10.1006/adnd.1995.1002

Axial and reflection asymmetry of the nuclear ground state
journal, September 2008

  • Möller, P.; Bengtsson, R.; Carlsson, B. G.
  • Atomic Data and Nuclear Data Tables, Vol. 94, Issue 5
  • DOI: 10.1016/j.adt.2008.05.002

Global systematics of octupole excitations in even-even nuclei
journal, November 2011


Octupole deformation properties of actinide isotopes within a mean-field approach
journal, August 2012


Fission half-lives of superheavy nuclei in a microscopic approach
journal, July 2012


Ground state octupole correlation energy with effective forces
journal, March 2015


Octupole deformation properties of the Barcelona-Catania-Paris energy density functionals
journal, March 2010


Fission properties for r -process nuclei
journal, February 2012


Octupole deformation in the nuclear chart based on the 3D Skyrme Hartree–Fock plus BCS model
journal, May 2017


Microscopic description of octupole shape-phase transitions in light actinide and rare-earth nuclei
journal, February 2014


Octupole deformation in the ground states of even-even nuclei: A global analysis within the covariant density functional theory
journal, April 2016


Octupole deformation in the ground states of even-even Z 96 ,   N 196 actinides and superheavy nuclei
journal, August 2017


Spectroscopy of reflection-asymmetric nuclei with relativistic energy density functionals
journal, November 2017


Enhanced T -Nonconserving Nuclear Moments
journal, November 1983


Atomic Parity Violation and the Nuclear Anapole Moment
journal, March 1997


Electric dipole moments of atoms, molecules, nuclei, and particles
journal, January 2019


Measurability of Nuclear Electric Dipole Moments
journal, December 1963


Collective T - and P -Odd Electromagnetic Moments in Nuclei with Octupole Deformations
journal, June 1996


Enhanced T -odd, P -odd electromagnetic moments in reflection asymmetric nuclei
journal, September 1997


Nuclear octupole correlations and the enhancement of atomic time-reversal violation
journal, February 2000


Time-reversal violating Schiff moment of 225 Ra
journal, August 2003


Enhanced nuclear Schiff moment and time-reversal violation in Th 229 -containing molecules
journal, March 2019


Correlating Schiff Moments in the Light Actinides with Octupole Moments
journal, December 2018


Self-consistent mean-field models for nuclear structure
journal, January 2003

  • Bender, Michael; Heenen, Paul-Henri; Reinhard, Paul-Gerhard
  • Reviews of Modern Physics, Vol. 75, Issue 1
  • DOI: 10.1103/RevModPhys.75.121

The limits of the nuclear landscape
journal, June 2012

  • Erler, Jochen; Birge, Noah; Kortelainen, Markus
  • Nature, Vol. 486, Issue 7404
  • DOI: 10.1038/nature11188

Central depression in nuclear density and its consequences for the shell structure of superheavy nuclei
journal, February 2005


Central depression in nucleonic densities: Trend analysis in the nuclear density functional theory approach
journal, August 2017


The limits of nuclear mass and charge
journal, June 2018


Hyperheavy nuclei: Existence and stability
journal, July 2018


Colloquium : Superheavy elements: Oganesson and beyond
journal, January 2019


Extension of the nuclear landscape to hyperheavy nuclei
journal, March 2019


Parity-projected calculations on octupole deformed nuclei
journal, March 1991


Enhancement of octupole strength in near spherical nuclei
journal, September 2016


Beyond relativistic mean-field approach for nuclear octupole excitations
journal, October 2015


Nuclear energy density optimization
journal, August 2010


Nuclear energy density optimization: Large deformations
journal, February 2012


Nuclear energy density optimization: Shell structure
journal, May 2014


New Skyrme effective forces for supernovae and neutron rich nuclei
journal, January 1995


Variations on a theme by Skyrme: A systematic study of adjustments of model parameters
journal, March 2009


The AME2016 atomic mass evaluation (II). Tables, graphs and references
journal, March 2017


Nuclear ground-state properties from mean-field calculations
journal, September 2002

  • Dobaczewski, J.; Nazarewicz, W.; Stoitsov, M. V.
  • The European Physical Journal A, Vol. 15, Issue 1-2
  • DOI: 10.1140/epja/i2001-10218-8

Systematic study of deformed nuclei at the drip lines and beyond
journal, November 2003


Relativistic Hartree?Bogoliubov theory: static and dynamic aspects of exotic nuclear structure
journal, April 2005


New relativistic mean-field interaction with density-dependent meson-nucleon couplings
journal, February 2005


The effective force NL3 revisited
journal, January 2009


New parametrization for the nuclear covariant energy density functional with a point-coupling interaction
journal, November 2010


Relativistic nuclear energy density functionals: Adjusting parameters to binding energies
journal, September 2008


A finite range pairing force for density functional theory in superfluid nuclei
journal, June 2009


Quantified limits of the nuclear landscape
journal, April 2020


Beyond the proton drip line: Bayesian analysis of proton-emitting nuclei
journal, January 2020


Studies of pear-shaped nuclei using accelerated radioactive beams
journal, May 2013

  • Gaffney, L. P.; Butler, P. A.; Scheck, M.
  • Nature, Vol. 497, Issue 7448
  • DOI: 10.1038/nature12073

Quadrupole deformed and octupole collective bands in 228Ra
journal, June 1998


Nuclear Data Sheets for A = 222
journal, November 2011


Observation of Octupole Structures in Radon and Radium Isotopes and Their Contrasting Behavior at High Spin
journal, April 1997


Spectroscopy of Rn, Ra and Th isotopes using multi-nucleon transfer reactions
journal, January 1999


The observation of vibrating pear-shapes in radon nuclei
journal, June 2019


Evolution of Octupole Deformation in Radium Nuclei from Coulomb Excitation of Radioactive Ra 222 and Ra 228 Beams
journal, January 2020


Collective E1 transitions in even-A Ra, Th, and U nuclei
journal, June 1993


Contrasting Behavior in Octupole Structures Observed at High Spin in 220 Ra and 222 Th
journal, August 1995


Half-life of Pu 228 and α decay of Np 228
journal, December 2003


Octupole deformation in neutron-rich barium isotopes
journal, December 1986


Influence of shell effects and stable octupole deformation on the E 1 and E 2 transition rates in the heavy-Ba region
journal, June 1990


Octupole deformation in 142,143Ba and 144Ce: new band structures in neutron-rich Ba-isotopes
journal, September 1995


Octupole correlations in neutron-rich, even-even barium isotopes
journal, January 1997


Direct Evidence of Octupole Deformation in Neutron-Rich Ba 144
journal, March 2016


Direct Evidence for Octupole Deformation in Ba 146 and the Origin of Large E 1 Moment Variations in Reflection-Asymmetric Nuclei
journal, April 2017


Octupole correlation effects near Z=56, N=88
journal, October 1988


Search for octupole correlations in neutron-rich Ce 148 nucleus
journal, May 2006


Observation of new levels and proposed octupole correlations in neutron-rich 150 Ce
journal, January 2012


High-spin octupole correlations in the N = 86, 146Nd and 148Sm nuclei
journal, April 1991


Reflection asymmetric states in 146Nd
journal, January 1996


Octupole collectivity in the ground band of Nd 148
journal, September 1993


Quadrupole and octupole collectivity in 148Nd
journal, June 1997


Evidence for enhanced electric dipole excitations in deformed rare earth nuclei near 2.5 MeV
journal, March 1992


Octupole correlations in the structure of 0 2 + bands in the N = 88 nuclei 150 Sm and 152 Gd
journal, April 2013


Enhanced nuclear Schiff moment in stable and metastable nuclei
journal, January 2020


Octupolly deformed nuclei near 112Ba
journal, March 1990


Octupole excitations in light xenon and barium nuclei
journal, August 1994


Excited states and deformation of 112Xe
journal, December 2001


Broken reflection symmetry in Xe 114
journal, October 1993


Direct observation of the Ba 114 Xe 110 Te 106 Sn 102 triple α -decay chain using position and time correlations
journal, August 2016


r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE
journal, December 2015


Fission properties of superheavy nuclei for r -process calculations
journal, March 2018

  • Giuliani, Samuel A.; Martínez-Pinedo, Gabriel; Robledo, Luis M.
  • Physical Review C, Vol. 97, Issue 3
  • DOI: 10.1103/PhysRevC.97.034323