Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition

S. Cruz; K. Wimmer; S. S. Bhattacharjee; P. C. Bender; G. Hackman; R. Krücken; F. Ames; C. Andreoiu; R. A.E. Austin; C. S. Bancroft; R. Braid; T. Bruhn; W. N. Catford; A. Cheeseman; A. Chester; D. S. Cross; C. Aa Diget; T. Drake; A. B. Garnsworthy; R. Kanungo; A. Knapton; W. Korten; K. Kuhn; J. Lassen; R. Laxdal; M. Marchetto; A. Matta; D. Miller; M. Moukaddam; N. A. Orr; N. Sachmpazidi; A. Sanetullaev; C. E. Svensson; N. Terpstra; C. Unsworth; P. J. Voss

doi:10.1103/PhysRevC.102.024335

Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition

S. Cruz, K. Wimmer^*, S. S. Bhattacharjee, P. C. Bender, G. Hackman, R. Krücken, F. Ames, C. Andreoiu, R. A.E. Austin, C. S. Bancroft, R. Braid, T. Bruhn, W. N. Catford, A. Cheeseman, A. Chester, D. S. Cross, C. Aa Diget, T. Drake, A. B. Garnsworthy, R. KanungoA. Knapton, W. Korten, K. Kuhn, J. Lassen, R. Laxdal, M. Marchetto, A. Matta, D. Miller, M. Moukaddam, N. A. Orr, N. Sachmpazidi, A. Sanetullaev, C. E. Svensson, N. Terpstra, C. Unsworth, P. J. Voss

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Background: Neutron-rich nuclei around neutron number N=60 show a dramatic shape transition from spherical ground states to prolate deformation in Sr98 and heavier nuclei. Purpose: The purpose of this study is to investigate the single-particle structure approaching the shape transitional region. Method: The level structures of neutron-rich Sr93,94,95 were studied via the H2(Sr94,95,96,t) one-neutron stripping reactions at TRIUMF using a beam energy of 5.5 AMeV. γ-rays emitted from excited states and recoiling charged particles were detected by using the TIGRESS and SHARC arrays, respectively. States were identified by gating on the excitation energy and, if possible, the coincident γ radiation.Results: Triton angular distributions for the reactions populating states in ejectile nuclei Sr93,94,95 were compared with distorted wave Born approximation calculations to assign and revise spin and parity quantum numbers and extract spectroscopic factors. The results were compared with shell-model calculations and the reverse (d,p) reactions and good agreement was obtained. Conclusions: The results for the H2(Sr94,t)Sr93 and H2(Sr95,t)Sr94 reactions are in good agreement with shell-model calculations. A two-level mixing analysis for the 0+ states in Sr94 suggest strong mixing of two shapes. For the H2(Sr96,t)Sr95 reaction the agreement with the shell-model is less good. The configuration of the ground state of Sr96 is already more complex than predicted, and therefore indications for the shape transition can already be observed before N=60.

Original language	English
Article number	024335
Journal	Physical Review C
Volume	102
Issue number	2
DOIs	https://doi.org/10.1103/PhysRevC.102.024335
Publication status	Published - 30 Aug 2020

Bibliographical note

Funding Information:
The efforts of the TRIUMF operations team in supplying the beam are highly appreciated. K.W. thanks A. M. Moro for his help regarding the input of the overlap function in fresco . We acknowledge support from the Science and Technologies Facility Council (UK, Grants No. EP/D060575/1 and No. ST/L005727/1), the National Science Foundation (US, Grant No. PHY-1306297), the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation and the British Columbia Knowledge and Development Fund. TRIUMF receives federal funding via a contribution through the National Research Council Canada. K.W. acknowledges the support from the Spanish Ministerio de Economía, Industria y Competitividad, Gobierno de España RYC-2017-22007.

Publisher Copyright:
© 2020 American Physical Society.

Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.

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10.1103/PhysRevC.102.024335

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Cruz, S., Wimmer, K., Bhattacharjee, S. S., Bender, P. C., Hackman, G., Krücken, R., Ames, F., Andreoiu, C., Austin, R. A. E., Bancroft, C. S., Braid, R., Bruhn, T., Catford, W. N., Cheeseman, A., Chester, A., Cross, D. S., Diget, C. A., Drake, T., Garnsworthy, A. B., ... Voss, P. J. (2020). Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition. Physical Review C, 102(2), Article 024335. https://doi.org/10.1103/PhysRevC.102.024335

@article{72cfa919d3964c5db6c91f24ca02d9ff,

title = "Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition",

abstract = "Background: Neutron-rich nuclei around neutron number N=60 show a dramatic shape transition from spherical ground states to prolate deformation in Sr98 and heavier nuclei. Purpose: The purpose of this study is to investigate the single-particle structure approaching the shape transitional region. Method: The level structures of neutron-rich Sr93,94,95 were studied via the H2(Sr94,95,96,t) one-neutron stripping reactions at TRIUMF using a beam energy of 5.5 AMeV. γ-rays emitted from excited states and recoiling charged particles were detected by using the TIGRESS and SHARC arrays, respectively. States were identified by gating on the excitation energy and, if possible, the coincident γ radiation.Results: Triton angular distributions for the reactions populating states in ejectile nuclei Sr93,94,95 were compared with distorted wave Born approximation calculations to assign and revise spin and parity quantum numbers and extract spectroscopic factors. The results were compared with shell-model calculations and the reverse (d,p) reactions and good agreement was obtained. Conclusions: The results for the H2(Sr94,t)Sr93 and H2(Sr95,t)Sr94 reactions are in good agreement with shell-model calculations. A two-level mixing analysis for the 0+ states in Sr94 suggest strong mixing of two shapes. For the H2(Sr96,t)Sr95 reaction the agreement with the shell-model is less good. The configuration of the ground state of Sr96 is already more complex than predicted, and therefore indications for the shape transition can already be observed before N=60.",

author = "S. Cruz and K. Wimmer and Bhattacharjee, {S. S.} and Bender, {P. C.} and G. Hackman and R. Kr{\"u}cken and F. Ames and C. Andreoiu and Austin, {R. A.E.} and Bancroft, {C. S.} and R. Braid and T. Bruhn and Catford, {W. N.} and A. Cheeseman and A. Chester and Cross, {D. S.} and Diget, {C. Aa} and T. Drake and Garnsworthy, {A. B.} and R. Kanungo and A. Knapton and W. Korten and K. Kuhn and J. Lassen and R. Laxdal and M. Marchetto and A. Matta and D. Miller and M. Moukaddam and Orr, {N. A.} and N. Sachmpazidi and A. Sanetullaev and Svensson, {C. E.} and N. Terpstra and C. Unsworth and Voss, {P. J.}",

note = "Funding Information: The efforts of the TRIUMF operations team in supplying the beam are highly appreciated. K.W. thanks A. M. Moro for his help regarding the input of the overlap function in fresco . We acknowledge support from the Science and Technologies Facility Council (UK, Grants No. EP/D060575/1 and No. ST/L005727/1), the National Science Foundation (US, Grant No. PHY-1306297), the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation and the British Columbia Knowledge and Development Fund. TRIUMF receives federal funding via a contribution through the National Research Council Canada. K.W. acknowledges the support from the Spanish Ministerio de Econom{\'i}a, Industria y Competitividad, Gobierno de Espa{\~n}a RYC-2017-22007. Publisher Copyright: {\textcopyright} 2020 American Physical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",

year = "2020",

month = aug,

day = "30",

doi = "10.1103/PhysRevC.102.024335",

language = "English",

volume = "102",

journal = "Physical Review C",

issn = "2469-9985",

publisher = "American Physical Society",

number = "2",

}

Cruz, S, Wimmer, K, Bhattacharjee, SS, Bender, PC, Hackman, G, Krücken, R, Ames, F, Andreoiu, C, Austin, RAE, Bancroft, CS, Braid, R, Bruhn, T, Catford, WN, Cheeseman, A, Chester, A, Cross, DS, Diget, CA, Drake, T, Garnsworthy, AB, Kanungo, R, Knapton, A, Korten, W, Kuhn, K, Lassen, J, Laxdal, R, Marchetto, M, Matta, A, Miller, D, Moukaddam, M, Orr, NA, Sachmpazidi, N, Sanetullaev, A, Svensson, CE, Terpstra, N, Unsworth, C & Voss, PJ 2020, 'Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition', Physical Review C, vol. 102, no. 2, 024335. https://doi.org/10.1103/PhysRevC.102.024335

TY - JOUR

T1 - Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition

AU - Cruz, S.

AU - Wimmer, K.

AU - Bhattacharjee, S. S.

AU - Bender, P. C.

AU - Hackman, G.

AU - Krücken, R.

AU - Ames, F.

AU - Andreoiu, C.

AU - Austin, R. A.E.

AU - Bancroft, C. S.

AU - Braid, R.

AU - Bruhn, T.

AU - Catford, W. N.

AU - Cheeseman, A.

AU - Chester, A.

AU - Cross, D. S.

AU - Diget, C. Aa

AU - Drake, T.

AU - Garnsworthy, A. B.

AU - Kanungo, R.

AU - Knapton, A.

AU - Korten, W.

AU - Kuhn, K.

AU - Lassen, J.

AU - Laxdal, R.

AU - Marchetto, M.

AU - Matta, A.

AU - Miller, D.

AU - Moukaddam, M.

AU - Orr, N. A.

AU - Sachmpazidi, N.

AU - Sanetullaev, A.

AU - Svensson, C. E.

AU - Terpstra, N.

AU - Unsworth, C.

AU - Voss, P. J.

N1 - Funding Information: The efforts of the TRIUMF operations team in supplying the beam are highly appreciated. K.W. thanks A. M. Moro for his help regarding the input of the overlap function in fresco . We acknowledge support from the Science and Technologies Facility Council (UK, Grants No. EP/D060575/1 and No. ST/L005727/1), the National Science Foundation (US, Grant No. PHY-1306297), the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation and the British Columbia Knowledge and Development Fund. TRIUMF receives federal funding via a contribution through the National Research Council Canada. K.W. acknowledges the support from the Spanish Ministerio de Economía, Industria y Competitividad, Gobierno de España RYC-2017-22007. Publisher Copyright: © 2020 American Physical Society. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/8/30

Y1 - 2020/8/30

N2 - Background: Neutron-rich nuclei around neutron number N=60 show a dramatic shape transition from spherical ground states to prolate deformation in Sr98 and heavier nuclei. Purpose: The purpose of this study is to investigate the single-particle structure approaching the shape transitional region. Method: The level structures of neutron-rich Sr93,94,95 were studied via the H2(Sr94,95,96,t) one-neutron stripping reactions at TRIUMF using a beam energy of 5.5 AMeV. γ-rays emitted from excited states and recoiling charged particles were detected by using the TIGRESS and SHARC arrays, respectively. States were identified by gating on the excitation energy and, if possible, the coincident γ radiation.Results: Triton angular distributions for the reactions populating states in ejectile nuclei Sr93,94,95 were compared with distorted wave Born approximation calculations to assign and revise spin and parity quantum numbers and extract spectroscopic factors. The results were compared with shell-model calculations and the reverse (d,p) reactions and good agreement was obtained. Conclusions: The results for the H2(Sr94,t)Sr93 and H2(Sr95,t)Sr94 reactions are in good agreement with shell-model calculations. A two-level mixing analysis for the 0+ states in Sr94 suggest strong mixing of two shapes. For the H2(Sr96,t)Sr95 reaction the agreement with the shell-model is less good. The configuration of the ground state of Sr96 is already more complex than predicted, and therefore indications for the shape transition can already be observed before N=60.

AB - Background: Neutron-rich nuclei around neutron number N=60 show a dramatic shape transition from spherical ground states to prolate deformation in Sr98 and heavier nuclei. Purpose: The purpose of this study is to investigate the single-particle structure approaching the shape transitional region. Method: The level structures of neutron-rich Sr93,94,95 were studied via the H2(Sr94,95,96,t) one-neutron stripping reactions at TRIUMF using a beam energy of 5.5 AMeV. γ-rays emitted from excited states and recoiling charged particles were detected by using the TIGRESS and SHARC arrays, respectively. States were identified by gating on the excitation energy and, if possible, the coincident γ radiation.Results: Triton angular distributions for the reactions populating states in ejectile nuclei Sr93,94,95 were compared with distorted wave Born approximation calculations to assign and revise spin and parity quantum numbers and extract spectroscopic factors. The results were compared with shell-model calculations and the reverse (d,p) reactions and good agreement was obtained. Conclusions: The results for the H2(Sr94,t)Sr93 and H2(Sr95,t)Sr94 reactions are in good agreement with shell-model calculations. A two-level mixing analysis for the 0+ states in Sr94 suggest strong mixing of two shapes. For the H2(Sr96,t)Sr95 reaction the agreement with the shell-model is less good. The configuration of the ground state of Sr96 is already more complex than predicted, and therefore indications for the shape transition can already be observed before N=60.

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U2 - 10.1103/PhysRevC.102.024335

DO - 10.1103/PhysRevC.102.024335

M3 - Article

AN - SCOPUS:85092103683

SN - 2469-9985

VL - 102

JO - Physical Review C

JF - Physical Review C

IS - 2

M1 - 024335

ER -

Single-particle structure in neutron-rich Sr isotopes approaching the N=60 shape transition

Abstract

Bibliographical note

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