Zhang, W., Cederwall, B., Doncel, M., Aktas, Ö., Ertoprak, A., Liotta, R., Qi, C., Grahn, T., Nara Singh, B. S., Cullen, D. M., Hodge, D., Giles, M., Stolze, S., Badran, H., Braunroth, T., Calverley, T., Cox, D. M., Fang, Y. D., Greenlees, P. T., … Valiente-Dobón, J. J. (2021). 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. Physics Letters B, 820, 136527. https://doi.org/10.1016/j.physletb.2021.136527
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
|Author:||Zhang, W.1; Cederwall, B.1; Doncel, M.2,3;|
1KTH Royal Inst Technol, S-10691 Stockholm, Sweden.
2Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England.
3Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden.
4Istanbul Univ, Fac Sci, Dept Phys, TR-34134 Istanbul, Turkey.
5Univ Jyvaskyla, Dept Phys, POB 35, FI-40014 Jyvaskyla, Finland.
6Univ Manchester, Sch Phys & Astron, Schuster Bldg, Manchester M13 9PL, Lancs, England.
7Univ West Scotland, Sch Comp Engn & Phys Sci, Paisley PA1 2BE, Renfrew, Scotland.
8Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany.
9Lund Univ, Dept Phys, S-22100 Lund, Sweden.
10Osaka Univ, Res Ctr Nucl Phys, Osaka 5670047, Japan.
11CEA DSM CNRS IN2P3, Grand Accelerateur Natl Ions Lourds GANIL, F-14076 Caen 5, France.
12Univ Oslo, Dept Phys, N-0316 Oslo, Norway.
13STFC Daresbury Lab, Warrington WA4 4AD, Cheshire, England.
14Univ Paris Saclay, IJCLab, IN2P3, CNRS, F-91405 Orsay, France.
15Sodankyla Geophys Observ, FI-99600 Sodankyla, Finland.
16Univ Manchester, Sch Med Sci, Div Canc Sci, Manchester M13 9PL, Lancs, England.
17Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy.
|Online Access:||PDF Full Text (PDF, 0.5 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2022033026210
|Publish Date:|| 2022-03-30
Lifetimes of low-lying excited states in the vi13/2⁺ 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; 4⁺1 → 2⁺1 )/B(E2; 2⁺1 → 0⁺gs) previously observed in several transitional rare-earth nuclides with even numbers of neutrons and protons, including the neighboring 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.
Physics letters. B
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
114 Physical sciences
This work was supported by the Swedish Research Council under Grant No. 2019-04880, the United Kingdom Science and Technology Facilities Council Transnational Access, project No. 262010 ENSAR, and the Academy of Finland under the Finnish Centre of Excellence Programme (Nuclear and Accelerator Based Physics Programme at JYFL). E.I., Y.D.F., and M.K.R. acknowledge support from the International Joint Research Promotion Program of Osaka University. W. Zhang acknowledges support from the China Scholarship Council under grant No. 201700260239. The authors acknowledge the support of the GAMMAPOOL for the JUROGAM detectors. Open Access funded by SCOAP3.
© 2021 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).