Lifetime measurements of excited states in 169,171,173Os : Persistence of anomalous B(E2) ratios in transitional rare earth nuclei in the presence of a decoupled i13/2 valence neutron
(2021) In Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 820.- Abstract
Lifetimes of low-lying excited states in the νi13/2+ bands of the neutron-deficient osmium isotopes 169,171,173Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) in 169Os, similar to the “anomalously” low values of the ratio B(E2;41+→21+)/B(E2;21+→0gs+) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring 168,170Os.... (More)
Lifetimes of low-lying excited states in the νi13/2+ bands of the neutron-deficient osmium isotopes 169,171,173Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) in 169Os, similar to the “anomalously” low values of the ratio B(E2;41+→21+)/B(E2;21+→0gs+) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring 168,170Os. Furthermore, the evolution of B(E2;21/2+→17/2+)/B(E2;17/2+→13/2+) with increasing neutron number in the odd-mass isotopic chain 169,171,173Os is observed to follow the same trend as observed previously in the even-even Os isotopes. These findings indicate that the possible quantum phase transition from a seniority conserving structure to a collective regime as a function of neutron number suggested for the even-even systems is maintained in these odd-mass osmium nuclei, with the odd valence neutron merely acting as a “spectator”. As for the even-even nuclei, the phenomenon is highly unexpected for nuclei that are not situated near closed shells.
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- author
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- publishing date
- 2021-09
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
- volume
- 820
- article number
- 136527
- publisher
- Elsevier
- external identifiers
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- scopus:85111240819
- ISSN
- 0370-2693
- DOI
- 10.1016/j.physletb.2021.136527
- language
- English
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- yes
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- ec37cc03-5702-40be-a705-69ea4906760d
- date added to LUP
- 2021-12-22 14:14:30
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- 2022-04-27 06:49:46
@article{ec37cc03-5702-40be-a705-69ea4906760d,
abstract = {{<p>Lifetimes of low-lying excited states in the νi<sub>13/2<sup>+</sup></sub> bands of the neutron-deficient osmium isotopes <sup>169,171,173</sup>Os have been measured for the first time using the recoil-distance Doppler shift and recoil-isomer tagging techniques. An unusually low value is observed for the ratio B(E2;21/2<sup>+</sup>→17/2<sup>+</sup>)/B(E2;17/2<sup>+</sup>→13/2<sup>+</sup>) in <sup>169</sup>Os, similar to the “anomalously” low values of the ratio B(E2;4<sub>1</sub><sup>+</sup>→2<sub>1</sub><sup>+</sup>)/B(E2;2<sub>1</sub><sup>+</sup>→0<sub>gs</sub><sup>+</sup>) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighbouring <sup>168,170</sup>Os. Furthermore, the evolution of B(E2;21/2<sup>+</sup>→17/2<sup>+</sup>)/B(E2;17/2<sup>+</sup>→13/2<sup>+</sup>) with increasing neutron number in the odd-mass isotopic chain <sup>169,171,173</sup>Os is observed to follow the same trend as observed previously in the even-even Os isotopes. These findings indicate that the possible quantum phase transition from a seniority conserving structure to a collective regime as a function of neutron number suggested for the even-even systems is maintained in these odd-mass osmium nuclei, with the odd valence neutron merely acting as a “spectator”. As for the even-even nuclei, the phenomenon is highly unexpected for nuclei that are not situated near closed shells.</p>}},
author = {{Zhang, W. and Cederwall, B. and Doncel, M. and Aktas and Ertoprak, A. and Liotta, R. and Qi, C. and Grahn, T. and Nara Singh, B. S. and Cullen, D. M. and Hodge, D. and Giles, M. and Stolze, S. and Badran, H. and Braunroth, T. and Calverley, T. and Cox, D. M. and Fang, Y. D. and Greenlees, P. T. and Hilton, J. and Ideguchi, E. and Julin, R. and Juutinen, S. and Kumar Raju, M. and Li, H. and Liu, H. and Matta, S. and Subramaniam, P. and Modamio, V. and Pakarinen, J. and Papadakis, P. and Partanen, J. and Petrache, C. M. and Rahkila, P. and Ruotsalainen, P. and Sandzelius, M. and Sarén, J. and Scholey, C. and Sorri, J. and Taylor, M. J. and Uusitalo, J. and Valiente-Dobón, J. J.}},
issn = {{0370-2693}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics}},
title = {{Lifetime measurements of excited states in <sup>169,171,173</sup>Os : Persistence of anomalous B(E2) ratios in transitional rare earth nuclei in the presence of a decoupled i<sub>13/2</sub> valence neutron}},
url = {{http://dx.doi.org/10.1016/j.physletb.2021.136527}},
doi = {{10.1016/j.physletb.2021.136527}},
volume = {{820}},
year = {{2021}},
}