Effects of one valence proton on seniority and angular momentum of neutrons in neutron-rich 122−131Sb51 isotopes
S. Biswas
(1)
,
A. Lemasson
(1)
,
M. Rejmund
(1)
,
A. Navin
(1)
,
Y.H. Kim
(1)
,
C. Michelagnoli
(1)
,
I. Stefan
(2)
,
R. Banik
,
P. Bednarczyk
,
S. Bhattacharya
,
S. Bhattacharyya
,
E. Clément
(1)
,
H.L. Crawford
,
G. de France
(1)
,
P. Fallon
,
G. Frémont
(1)
,
J. Goupil
(1)
,
B. Jacquot
(1)
,
H.J. Li
(1)
,
J. Ljungvall
(3)
,
A. Maj
,
L. Ménager
(1)
,
V. Morel
(1)
,
R. Palit
,
R.M. Pérez-Vidal
,
J. Ropert
(1)
,
D. Barrientos
,
G. Benzoni
,
B. Birkenbach
,
A.J. Boston
,
H.C. Boston
,
B. Cederwall
,
J. Collado
,
D.M. Cullen
,
P. Désesquelles
(3)
,
C. Domingo-Pardo
,
J. Dudouet
(3, 4)
,
J. Eberth
,
V. González
,
L.J. Harkness-Brennan
,
H. Hess
,
A. Jungclaus
,
W. Korten
(5)
,
M. Labiche
,
A. Lefevre
(1)
,
R. Menegazzo
,
D. Mengoni
,
B. Million
,
D.R. Napoli
,
A. Pullia
,
B. Quintana
,
D. Ralet
(3)
,
F. Recchia
,
P. Reiter
,
F. Saillant
(1)
,
M.D. Salsac
(5)
,
E. Sanchis
,
O. Stezowski
(4)
,
Ch. Theisen
(5)
,
J.J. Valiente-Dobón
,
M. Zielińska
(5)
A. Lemasson
- Fonction : Auteur
- PersonId : 3871
- IdHAL : antoine-lemasson
- ORCID : 0000-0002-9434-8520
- IdRef : 152663169
I. Stefan
- Fonction : Auteur
- PersonId : 179537
- IdHAL : iulian-stefan
- ORCID : 0000-0001-7923-8908
- IdRef : 114633401
R. Banik
- Fonction : Auteur
P. Bednarczyk
- Fonction : Auteur
S. Bhattacharya
- Fonction : Auteur
S. Bhattacharyya
- Fonction : Auteur
H.L. Crawford
- Fonction : Auteur
P. Fallon
- Fonction : Auteur
J. Ljungvall
- Fonction : Auteur
- PersonId : 737836
- IdHAL : joa-ljungvall
- ORCID : 0000-0003-1938-1889
- IdRef : 234661593
A. Maj
- Fonction : Auteur
- PersonId : 755162
- ORCID : 0000-0002-1142-8067
- IdRef : 219941858
R. Palit
- Fonction : Auteur
R.M. Pérez-Vidal
- Fonction : Auteur
D. Barrientos
- Fonction : Auteur
G. Benzoni
- Fonction : Auteur
- PersonId : 755374
- ORCID : 0000-0002-7938-0338
B. Birkenbach
- Fonction : Auteur
A.J. Boston
- Fonction : Auteur
H.C. Boston
- Fonction : Auteur
B. Cederwall
- Fonction : Auteur
J. Collado
- Fonction : Auteur
D.M. Cullen
- Fonction : Auteur
C. Domingo-Pardo
- Fonction : Auteur
J. Dudouet
- Fonction : Auteur
- PersonId : 181375
- IdHAL : jeremie-dudouet
- ORCID : 0000-0002-9018-6763
- IdRef : 191249076
J. Eberth
- Fonction : Auteur
V. González
- Fonction : Auteur
L.J. Harkness-Brennan
- Fonction : Auteur
H. Hess
- Fonction : Auteur
A. Jungclaus
- Fonction : Auteur
M. Labiche
- Fonction : Auteur
R. Menegazzo
- Fonction : Auteur
D. Mengoni
- Fonction : Auteur
B. Million
- Fonction : Auteur
D.R. Napoli
- Fonction : Auteur
A. Pullia
- Fonction : Auteur
B. Quintana
- Fonction : Auteur
F. Recchia
- Fonction : Auteur
P. Reiter
- Fonction : Auteur
E. Sanchis
- Fonction : Auteur
J.J. Valiente-Dobón
- Fonction : Auteur
Résumé
Background: Levels fulfilling the seniority scheme and relevant isomers are commonly observed features in semimagic nuclei; for example, in Sn isotopes (Z=50). Seniority isomers in Sn, with dominantly pure neutron configurations, directly probe the underlying neutron-neutron (νν) interaction. Furthermore, an addition of a valence proton particle or hole, through neutron-proton (νπ) interaction, affects the neutron seniority as well as the angular momentum. Purpose: Benchmark the reproducibility of the experimental observables, like the excitation energies (EX) and the reduced electric-quadrupole transition probabilities [B(E2)], with the results obtained from shell-model interactions for neutron-rich Sn and Sb isotopes with N<82. Study the sensitivity of the aforementioned experimental observables to the model interaction components. Furthermore, explore from a microscopic point of view the structural similarity between the isomers in Sn and Sb, and thus the importance of the valence proton. Methods: The neutron-rich Sb122–131 isotopes were produced as fission fragments in the reaction Be9(U238, f) with 6.2 MeV/u beam energy. A unique setup, consisting of AGATA, VAMOS++, and EXOGAM detectors, was used which enabled the prompt-delayed γ-ray spectroscopy of fission fragments in the time range of 100 ns to 200μs. Results: New isomers and prompt and delayed transitions were established in the even-A Sb122–130 isotopes. In the odd-A Sb123–131 isotopes, new prompt and delayed γ-ray transitions were identified, in addition to the confirmation of the previously known isomers. The half-lives of the isomeric states and the B(E2) transition probabilities of the observed transitions depopulating these isomers were extracted. Conclusions: The experimental data was compared with the theoretical results obtained in the framework of large-scale shell-model (LSSM) calculations in a restricted model space. Modifications of several components of the shell-model interaction were introduced to obtain a consistent agreement with the excitation energies and the B(E2) transition probabilities in neutron-rich Sn and Sb isotopes. The isomeric configurations in Sn and Sb were found to be relatively pure. Furthermore, the calculations revealed that the presence of a single valence proton, mainly in the g7/2 orbital in Sb isotopes, leads to significant mixing (due to the νπ interaction) of (i) the neutron seniorities (υν) and (ii) the neutron angular momentum (Iν). The above features have a weak impact on the excitation energies, but have an important impact on the B(E2) transition probabilities. In addition, a constancy of the relative excitation energies irrespective of neutron seniority and neutron number in Sn and Sb was observed.