Axial and triaxial degrees of freedom in $^{72}$Zn
S Hellgartner
,
D Mücher
,
K Wimmer
,
V Bildstein
,
J.L Egido
,
R Gernhäuser
,
R Krücken
,
A.K Nowak
,
M Zielinska
(1)
,
C Bauer
,
M.L.L Benito
,
S Bottoni
,
H de Witte
,
J Elseviers
,
D Fedorov
,
F Flavigny
(2)
,
A Illana
,
M Klintefjord
,
T Kröll
,
R Lutter
,
B Marsh
,
R Orlandi
,
J Pakarinen
,
R Raabe
,
E Rapisarda
,
S Reichert
,
P Reiter
,
M Scheck
,
M Seidlitz
,
B Siebeck
,
E Siesling
,
T Steinbach
,
T Stora
,
M Vermeulen
,
D Voulot
,
N Warr
,
F.J.C Wenander
S Hellgartner
- Fonction : Auteur
D Mücher
- Fonction : Auteur
K Wimmer
- Fonction : Auteur
V Bildstein
- Fonction : Auteur
J.L Egido
- Fonction : Auteur
R Gernhäuser
- Fonction : Auteur
R Krücken
- Fonction : Auteur
A.K Nowak
- Fonction : Auteur
C Bauer
- Fonction : Auteur
M.L.L Benito
- Fonction : Auteur
S Bottoni
- Fonction : Auteur
H de Witte
- Fonction : Auteur
J Elseviers
- Fonction : Auteur
D Fedorov
- Fonction : Auteur
A Illana
- Fonction : Auteur
M Klintefjord
- Fonction : Auteur
T Kröll
- Fonction : Auteur
R Lutter
- Fonction : Auteur
B Marsh
- Fonction : Auteur
R Orlandi
- Fonction : Auteur
J Pakarinen
- Fonction : Auteur
R Raabe
- Fonction : Auteur
E Rapisarda
- Fonction : Auteur
S Reichert
- Fonction : Auteur
P Reiter
- Fonction : Auteur
M Scheck
- Fonction : Auteur
M Seidlitz
- Fonction : Auteur
B Siebeck
- Fonction : Auteur
E Siesling
- Fonction : Auteur
T Steinbach
- Fonction : Auteur
T Stora
- Fonction : Auteur
M Vermeulen
- Fonction : Auteur
D Voulot
- Fonction : Auteur
N Warr
- Fonction : Auteur
F.J.C Wenander
- Fonction : Auteur
Résumé
The unstable nucleus 72Zn has been studied using multiple safe Coulomb excitation in inverse kinematics. The experiment was performed at the REX-ISOLDE facility at CERN making first use of the silicon detector array C-REX in combination with the γ-ray spectrometer Miniball. The high angular coverage of C-REX allowed to determine the reduced transition strengths for the decay of the yrast , and as well as of the and states in 72Zn. The quadrupole moments of the , and states were extracted. Using model independent quadrupole invariants, the ground state of 72Zn was found to have an average deformation in the γ degree of freedom close to maximum triaxiality. In comparison to experimental data in zinc isotopes with , the collectivity of the state in neutron-rich 72Zn is significantly larger, indicating a collective yrast band based on the ground state of 72Zn. In contrast, a low experimental strength was determined, indicating a different structure for the state. Shell-model calculations propose a state featuring a larger fraction of the (spherical) closed-shell configuration in its wave function than for the ground state. The results were also compared with beyond mean field calculations which corroborate the large deformation in the γ degree of freedom, while pointing to a more deformed state. These experimental and theoretical findings establish the importance of the γ degree of freedom in the ground state of 72Zn, located between the 68,70Ni nuclei that have spherical ground states, and 76Ge, which has a rigid triaxial shape.
Format du dépôt | Fichier |
---|---|
Type de dépôt | Article dans une revue |
Titre |
en
Axial and triaxial degrees of freedom in $^{72}$Zn
|
Résumé |
en
The unstable <math altimg="si1.svg"><mi>N</mi><mo linebreak="goodbreak" linebreakstyle="after">=</mo><mn>42</mn></math> nucleus <sup loc="post">72</sup>Zn has been studied using multiple safe Coulomb excitation in inverse kinematics. The experiment was performed at the REX-ISOLDE facility at CERN making first use of the silicon detector array C-REX in combination with the γ-ray spectrometer Miniball. The high angular coverage of C-REX allowed to determine the reduced transition strengths for the decay of the yrast <math altimg="si2.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math>, <math altimg="si3.svg"><msubsup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> and <math altimg="si4.svg"><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> as well as of the <math altimg="si5.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> and <math altimg="si6.svg"><msubsup><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> states in <sup loc="post">72</sup>Zn. The quadrupole moments of the <math altimg="si3.svg"><msubsup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math>, <math altimg="si4.svg"><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> and <math altimg="si6.svg"><msubsup><mrow><mn>2</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> states were extracted. Using model independent quadrupole invariants, the ground state of <sup loc="post">72</sup>Zn was found to have an average deformation in the γ degree of freedom close to maximum triaxiality. In comparison to experimental data in zinc isotopes with <math altimg="si7.svg"><mi>N</mi><mo linebreak="goodbreak" linebreakstyle="after"><</mo><mn>40</mn></math>, the collectivity of the <math altimg="si4.svg"><msubsup><mrow><mn>4</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> state in neutron-rich <sup loc="post">72</sup>Zn is significantly larger, indicating a collective yrast band based on the ground state of <sup loc="post">72</sup>Zn. In contrast, a low experimental <math altimg="si8.svg"><mi>B</mi><mo stretchy="false">(</mo><mi>E</mi><mn>2</mn><mo>;</mo><msubsup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup><mo stretchy="false">→</mo><msubsup><mrow><mn>2</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup><mo stretchy="false">)</mo></math> strength was determined, indicating a different structure for the <math altimg="si5.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> state. Shell-model calculations propose a <math altimg="si5.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> state featuring a larger fraction of the (spherical) <math altimg="si9.svg"><mi>N</mi><mo linebreak="goodbreak" linebreakstyle="after">=</mo><mn>40</mn></math> closed-shell configuration in its wave function than for the <math altimg="si2.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>1</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> ground state. The results were also compared with beyond mean field calculations which corroborate the large deformation in the γ degree of freedom, while pointing to a more deformed <math altimg="si5.svg"><msubsup><mrow><mn>0</mn></mrow><mrow><mn>2</mn></mrow><mrow><mo linebreak="badbreak" linebreakstyle="after">+</mo></mrow></msubsup></math> state. These experimental and theoretical findings establish the importance of the γ degree of freedom in the ground state of <sup loc="post">72</sup>Zn, located between the <sup loc="post">68,70</sup>Ni nuclei that have spherical ground states, and <sup loc="post">76</sup>Ge, which has a rigid triaxial shape.
|
Auteur(s) |
S Hellgartner
, D Mücher
, K Wimmer
, V Bildstein
, J.L Egido
, R Gernhäuser
, R Krücken
, A.K Nowak
, M Zielinska
1
, C Bauer
, M.L.L Benito
, S Bottoni
, H de Witte
, J Elseviers
, D Fedorov
, F Flavigny
2
, A Illana
, M Klintefjord
, T Kröll
, R Lutter
, B Marsh
, R Orlandi
, J Pakarinen
, R Raabe
, E Rapisarda
, S Reichert
, P Reiter
, M Scheck
, M Seidlitz
, B Siebeck
, E Siesling
, T Steinbach
, T Stora
, M Vermeulen
, D Voulot
, N Warr
, F.J.C Wenander
1
IRFU -
Institut de Recherches sur les lois Fondamentales de l'Univers
( 53946 )
- CEA Saclay
F-91191 Gif sur Yvette cedex
- France
2
LPCC -
Laboratoire de physique corpusculaire de Caen
( 130 )
- ENSICAEN - 6, boulevard du Marechal Juin 14050 Caen Cedex
- France
|
Volume |
841
|
Page/Identifiant |
137933
|
Date de publication |
2023
|
Audience |
Internationale
|
Comité de lecture |
Oui
|
Vulgarisation |
Non
|
Langue du document |
Anglais
|
Nom de la revue |
|
Domaine(s) |
|
Mots-clés |
en
Multiple Coulomb excitation, Zn, sub-shell closure, Triaxiality
|
DOI | 10.1016/j.physletb.2023.137933 |
inSPIRE HEP | 2656164 |
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