Collectivity in the light radon nuclei measured directly via Coulomb excitation

Gaffney, L. P.; Robinson, A. P.; Jenkins, D. G.; Andreyev, A. N.; Bender, M.; Blazhev, A.; Bree, N.; Bruyneel, B.; Butler, P. A.; Cocolios, T. E.; Davinson, T.; Deacon, A. N.; De Witte, H.; DiJulio, Douglas; Diriken, J.; Ekström, Andreas; Fransen, Ch.; Freeman, S. J.; Geibel, K.; Grahn, T.; Hadinia, B.; Hass, M.; Heenen, P. -H.; Hess, H.; Huyse, M.; Jakobsson, U.; Kesteloot, N.; Konki, J.; Kroell, Th.; Kumar, V.; Ivanov, O.; Martin-Haugh, S.; Muecher, D.; Orlandi, R.; Pakarinen, J.; Petts, A.; Peura, P.; Rahkila, P.; Reiter, P.; Scheck, M.; Seidlitz, M.; Singh, K.; Smith, J. F.; Van de Walle, J.; Van Duppen, P.; Voulot, D.; Wadsworth, R.; Warr, N.; Wenander, F.; Wimmer, K.

Collectivity in the light radon nuclei measured directly via Coulomb excitation

Mark

Gaffney, L. P. ; Robinson, A. P. ; Jenkins, D. G. ; Andreyev, A. N. ; Bender, M. ; Blazhev, A. ; Bree, N. ; Bruyneel, B. ; Butler, P. A. and Cocolios, T. E. , et al. (2015) In Physical Review C (Nuclear Physics) 91(6).

Abstract: Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z = 82 and the neutron midshell at N = 104. Purpose: Evidence for shape coexistence has been inferred from a-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn-202 and Rn-204 were studied by means of low-energy... (More); Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z = 82 and the neutron midshell at N = 104. Purpose: Evidence for shape coexistence has been inferred from a-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn-202 and Rn-204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 2(1)(+) state was extracted for both Rn-202 and Rn-204, corresponding to B(E2; 2(1)(+) -> 0(1)(+)) = 29(-8)(+8) and 43(-12)(+17) W.u., respectively. Additionally, E2 matrix elements connecting the 2(1)(+) state with the 4(1)(+) and 2(2)(+) states were determined in Rn-202. No excited 0(+) states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced. (Less)

Please use this url to cite or link to this publication: https://lup.lub.lu.se/record/7596836

author

Gaffney, L. P. ; Robinson, A. P. ; Jenkins, D. G. ; Andreyev, A. N. ; Bender, M. ; Blazhev, A. ; Bree, N. ; Bruyneel, B. ; Butler, P. A. and Cocolios, T. E. , et al. (More)

Gaffney, L. P. ; Robinson, A. P. ; Jenkins, D. G. ; Andreyev, A. N. ; Bender, M. ; Blazhev, A. ; Bree, N. ; Bruyneel, B. ; Butler, P. A. ; Cocolios, T. E. ; Davinson, T. ; Deacon, A. N. ; De Witte, H. ; DiJulio, Douglas ^LU ; Diriken, J. ; Ekström, Andreas ^LU ; Fransen, Ch. ; Freeman, S. J. ; Geibel, K. ; Grahn, T. ; Hadinia, B. ; Hass, M. ; Heenen, P. -H. ; Hess, H. ; Huyse, M. ; Jakobsson, U. ; Kesteloot, N. ; Konki, J. ; Kroell, Th. ; Kumar, V. ; Ivanov, O. ; Martin-Haugh, S. ; Muecher, D. ; Orlandi, R. ; Pakarinen, J. ; Petts, A. ; Peura, P. ; Rahkila, P. ; Reiter, P. ; Scheck, M. ; Seidlitz, M. ; Singh, K. ; Smith, J. F. ; Van de Walle, J. ; Van Duppen, P. ; Voulot, D. ; Wadsworth, R. ; Warr, N. ; Wenander, F. ; Wimmer, K. ; Wrzosek-Lipska, K. and Zielinska, M. (Less)

organization

Nuclear physics

publishing date

2015

type

Contribution to journal

publication status

published

subject

Subatomic Physics

in

Physical Review C (Nuclear Physics)

volume

91

issue

6

article number

064313

publisher

American Physical Society

external identifiers

wos:000356582200002
scopus:84936791410

ISSN

0556-2813

DOI

10.1103/PhysRevC.91.064313

language

English

LU publication?

yes

id

bf96aca5-c473-49b7-a740-0ae23a2138f9 (old id 7596836)

date added to LUP

2016-04-01 14:22:11

date last changed

2022-02-04 20:31:11

@article{bf96aca5-c473-49b7-a740-0ae23a2138f9,
  abstract     = {{Background: Shape coexistence in heavy nuclei poses a strong challenge to state-of-the-art nuclear models, where several competing shape minima are found close to the ground state. A classic region for investigating this phenomenon is in the region around Z = 82 and the neutron midshell at N = 104. Purpose: Evidence for shape coexistence has been inferred from a-decay measurements, laser spectroscopy, and in-beam measurements. While the latter allow the pattern of excited states and rotational band structures to be mapped out, a detailed understanding of shape coexistence can only come from measurements of electromagnetic matrix elements. Method: Secondary, radioactive ion beams of Rn-202 and Rn-204 were studied by means of low-energy Coulomb excitation at the REX-ISOLDE in CERN. Results: The electric-quadrupole (E2) matrix element connecting the ground state and first excited 2(1)(+) state was extracted for both Rn-202 and Rn-204, corresponding to B(E2; 2(1)(+) -&gt; 0(1)(+)) = 29(-8)(+8) and 43(-12)(+17) W.u., respectively. Additionally, E2 matrix elements connecting the 2(1)(+) state with the 4(1)(+) and 2(2)(+) states were determined in Rn-202. No excited 0(+) states were observed in the current data set, possibly owing to a limited population of second-order processes at the currently available beam energies. Conclusions: The results are discussed in terms of collectivity and the deformation of both nuclei studied is deduced to be weak, as expected from the low-lying level-energy schemes. Comparisons are also made to state-of-the-art beyond-mean-field model calculations and the magnitude of the transitional quadrupole moments are well reproduced.}},
  author       = {{Gaffney, L. P. and Robinson, A. P. and Jenkins, D. G. and Andreyev, A. N. and Bender, M. and Blazhev, A. and Bree, N. and Bruyneel, B. and Butler, P. A. and Cocolios, T. E. and Davinson, T. and Deacon, A. N. and De Witte, H. and DiJulio, Douglas and Diriken, J. and Ekström, Andreas and Fransen, Ch. and Freeman, S. J. and Geibel, K. and Grahn, T. and Hadinia, B. and Hass, M. and Heenen, P. -H. and Hess, H. and Huyse, M. and Jakobsson, U. and Kesteloot, N. and Konki, J. and Kroell, Th. and Kumar, V. and Ivanov, O. and Martin-Haugh, S. and Muecher, D. and Orlandi, R. and Pakarinen, J. and Petts, A. and Peura, P. and Rahkila, P. and Reiter, P. and Scheck, M. and Seidlitz, M. and Singh, K. and Smith, J. F. and Van de Walle, J. and Van Duppen, P. and Voulot, D. and Wadsworth, R. and Warr, N. and Wenander, F. and Wimmer, K. and Wrzosek-Lipska, K. and Zielinska, M.}},
  issn         = {{0556-2813}},
  language     = {{eng}},
  number       = {{6}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review C (Nuclear Physics)}},
  title        = {{Collectivity in the light radon nuclei measured directly via Coulomb excitation}},
  url          = {{http://dx.doi.org/10.1103/PhysRevC.91.064313}},
  doi          = {{10.1103/PhysRevC.91.064313}},
  volume       = {{91}},
  year         = {{2015}},
}

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Collectivity in the light radon nuclei measured directly via Coulomb excitation