Limits on assigning a shape to a nucleus

Poves, A.; Nowacki, F.; Alhassid, Y.

doi:10.1103/physrevc.101.054307

Title: Limits on assigning a shape to a nucleus

Abstract

The interpretation of nuclear observables in the laboratory frame in terms of the intrinsic deformation parameters β and γ is a classical theme in nuclear structure. Here we use the quadrupole invariants, calculated within the framework of the configuration-interaction shell model, to clarify the meaning and limitations of nuclear shapes. In this work we introduce a novel method that enables us to calculate accurately higher-order invariants and, therefore, the fluctuations in both β and γ. We find that the shape parameter β often has a non-negligible degree of softness and that the angle γ is usually characterized by large fluctuations, rendering its effective value not meaningful. Contrary to common belief, we conclude that doubly magic nuclei are not spherical, because the notion of a well-defined shape does not apply to them.

Authors:

^[1]; Nowacki, F. ^[2]; Alhassid, Y. ^[3]

Univ. Autonoma de Madrid (Spain)
Université de Strasbourg (France); Centre National de la Recherche Scientifique (CNRS), Strasbourg (France). Inst. Pluridisciplinaire Hubert CURIEN (IPHC)
Yale Univ., New Haven, CT (United States)

Publication Date:: Mon May 11 00:00:00 EDT 2020

Research Org.:: Yale Univ., New Haven, CT (United States)

Sponsoring Org.:: Ministerio de Ciencia, Innovación y Universidades; USDOE Office of Science (SC)

OSTI Identifier:: 1803867

Grant/Contract Number:: SC0019521; PGC-2018-94583

Resource Type:: Accepted Manuscript

Journal Name:: Physical Review C

Additional Journal Information:: Journal Volume: 101; Journal Issue: 5; Journal ID: ISSN 2469-9985

Publisher:: American Physical Society (APS)

Country of Publication:: United States

Language:: English

Subject:: 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Physics

Citation Formats


                    Poves, A., Nowacki, F., and Alhassid, Y. Limits on assigning a shape to a nucleus.  United States: N. p., 2020. 
Web.  doi:10.1103/physrevc.101.054307.

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                    Poves, A., Nowacki, F., & Alhassid, Y. Limits on assigning a shape to a nucleus.  United States.  https://doi.org/10.1103/physrevc.101.054307

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                    Poves, A., Nowacki, F., and Alhassid, Y. Mon .  
"Limits on assigning a shape to a nucleus".  United States.  https://doi.org/10.1103/physrevc.101.054307.  https://www.osti.gov/servlets/purl/1803867.

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@article{osti_1803867,

  title        = {Limits on assigning a shape to a nucleus},

  author       = {Poves, A. and Nowacki, F. and Alhassid, Y.},

  abstractNote = {The interpretation of nuclear observables in the laboratory frame in terms of the intrinsic deformation parameters β and γ is a classical theme in nuclear structure. Here we use the quadrupole invariants, calculated within the framework of the configuration-interaction shell model, to clarify the meaning and limitations of nuclear shapes. In this work we introduce a novel method that enables us to calculate accurately higher-order invariants and, therefore, the fluctuations in both β and γ. We find that the shape parameter β often has a non-negligible degree of softness and that the angle γ is usually characterized by large fluctuations, rendering its effective value not meaningful. Contrary to common belief, we conclude that doubly magic nuclei are not spherical, because the notion of a well-defined shape does not apply to them.},

  doi          = {10.1103/physrevc.101.054307},

  journal      = {Physical Review C},

  number       = 5,

  volume       = 101,

  place        = {United States},

  year         = {Mon May 11 00:00:00 EDT 2020},

  month        = {Mon May 11 00:00:00 EDT 2020}

}

Copy to clipboard

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Works referenced in this record:

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Title: Limits on assigning a shape to a nucleus

Abstract

Citation Formats

Triaxiality in selenium-76 journal, May 2019

Superdeformed and Triaxial States in Ca 42 journal, August 2016

N 28 68 i 40 : Magicity versus Superfluidity journal, February 2002

Nuclear deformation in the laboratory frame journal, January 2018

Evidence for Rigid Triaxial Deformation in Ge 76 from a Model-Independent Analysis journal, September 2019

Mean field and beyond description of nuclear structure with the Gogny force: a review journal, December 2018

Rotational states in even atomic nuclei journal, September 1958

Shell model structure of 43 S and 44 S re-examined journal, May 2014

Meson-exchange enhancement in first-forbidden β transitions: The case of 50 K and 38 Ca journal, October 1998

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Island of inversion around Cr 64 journal, November 2010

Realistic collective nuclear Hamiltonian journal, October 1996

Statistical theory of deformation distributions in nuclear spectra journal, September 2018

Nuclear Deformation at Finite Temperature journal, December 2014

sd -shell observables for the USDA and USDB Hamiltonians journal, December 2008

Merging of the islands of inversion at N = 20 and N = 28 journal, July 2014

Unveiling the Intruder Deformed 0 2 + State in Si 34 journal, August 2012

Theoretical spectroscopy and the fp shell journal, April 1981

Discovery of a new isomeric state in 68 Ni: Evidence for a highly deformed proton intruder state journal, March 2012

Shell-model-based deformation analysis of light cadmium isotopes journal, July 2017

Shape coexistence in atomic nuclei journal, November 2011

Quadrupole collectivity in Ca 42 from low-energy Coulomb excitation with AGATA journal, February 2018

The shell model as a unified view of nuclear structure journal, June 2005

New effective interaction for 0 ℏ ω shell-model calculations in the sd − pf valence space journal, January 2009

Configuration mixing and relative transition rates between low-spin states in 68 Ni journal, October 2013

Evidence for rigid triaxial deformation at low energy in 76 Ge journal, April 2013

Triaxiality in selenium-76
journal, May 2019

Superdeformed and Triaxial States in ${}^{42}{Ca}$
journal, August 2016

${}_{28}^{68}N i_{40}$ : Magicity versus Superfluidity
journal, February 2002

Nuclear deformation in the laboratory frame
journal, January 2018

Evidence for Rigid Triaxial Deformation in ${}^{76}{Ge}$ from a Model-Independent Analysis
journal, September 2019

Mean field and beyond description of nuclear structure with the Gogny force: a review
journal, December 2018

Rotational states in even atomic nuclei
journal, September 1958

Shell model structure of $^{43} S$ and $^{44} S$ re-examined
journal, May 2014

Meson-exchange enhancement in first-forbidden $β$ transitions: The case of $^{50} K$ and $^{38} Ca$
journal, October 1998

Nuclear Shapes Studied by Coulomb Excitation
journal, December 1986

Intrinsic Quadrupole Moments and Shapes of Nuclear Ground States and Excited States
journal, January 1972

Island of inversion around ${}^{64}{Cr}$
journal, November 2010

Realistic collective nuclear Hamiltonian
journal, October 1996

Statistical theory of deformation distributions in nuclear spectra
journal, September 2018

Nuclear Deformation at Finite Temperature
journal, December 2014

$sd$ -shell observables for the USDA and USDB Hamiltonians
journal, December 2008

Merging of the islands of inversion at $N = 20$ and $N = 28$
journal, July 2014

Unveiling the Intruder Deformed $0_{2}^{+}$ State in ${}^{34}{Si}$
journal, August 2012

Theoretical spectroscopy and the fp shell
journal, April 1981

Discovery of a new isomeric state in $^{68}$ Ni: Evidence for a highly deformed proton intruder state
journal, March 2012

Shell-model-based deformation analysis of light cadmium isotopes
journal, July 2017

Shape coexistence in atomic nuclei
journal, November 2011

Quadrupole collectivity in ${}^{42}{Ca}$ from low-energy Coulomb excitation with AGATA
journal, February 2018

The shell model as a unified view of nuclear structure
journal, June 2005

New effective interaction for $0 ℏ ω$ shell-model calculations in the $sd − pf$ valence space
journal, January 2009

Configuration mixing and relative transition rates between low-spin states in $^{68}$ Ni
journal, October 2013

Evidence for rigid triaxial deformation at low energy in $^{76}$ Ge
journal, April 2013