Level structures of 56,58Ca cast doubt on a doubly magic 60Ca

S. Chen; F. Browne; P. Doornenbal; J. Lee; A. Obertelli; Y. Tsunoda; T. Otsuka; Y. Chazono; G. Hagen; J. D. Holt; G. R. Jansen; K. Ogata; N. Shimizu; Y. Utsuno; K. Yoshida; N. L. Achouri; H. Baba; D. Calvet; F. Château; N. Chiga; A. Corsi; M. L. Cortés; A. Delbart; J. M. Gheller; A. Giganon; A. Gillibert; C. Hilaire; T. Isobe; T. Kobayashi; Y. Kubota; V. Lapoux; H. N. Liu; T. Motobayashi; I. Murray; H. Otsu; V. Panin; N. Paul; W. Rodriguez; H. Sakurai; M. Sasano; D. Steppenbeck; L. Stuhl; Y. L. Sun; Y. Togano; T. Uesaka; K. Wimmer; K. Yoneda; O. Aktas; T. Aumann; L. X. Chung; F. Flavigny; S. Franchoo; I. Gasparic; R. B. Gerst; J. Gibelin; K. I. Hahn; D. Kim; T. Koiwai; Y. Kondo; P. Koseoglou; C. Lehr; B. D. Linh; T. Lokotko; M. MacCormick; K. Moschner; T. Nakamura; S. Y. Park; D. Rossi; E. Sahin; P. A. Söderström; D. Sohler; S. Takeuchi; H. Törnqvist; V. Vaquero; V. Wagner; S. Wang; V. Werner; X. Xu; H. Yamada; D. Yan; Z. Yang; M. Yasuda; L. Zanetti

doi:10.1016/j.physletb.2023.138025

Level structures of ^56,58Ca cast doubt on a doubly magic ⁶⁰Ca

S. Chen, F. Browne, P. Doornenbal, J. Lee, A. Obertelli, Y. Tsunoda, T. Otsuka, Y. Chazono, G. Hagen, J. D. Holt, G. R. Jansen, K. Ogata, N. Shimizu, Y. Utsuno, K. Yoshida, N. L. Achouri, H. Baba, D. Calvet, F. Château, N. ChigaA. Corsi, M. L. Cortés, A. Delbart, J. M. Gheller, A. Giganon, A. Gillibert, C. Hilaire, T. Isobe, T. Kobayashi, Y. Kubota, V. Lapoux, H. N. Liu, T. Motobayashi, I. Murray, H. Otsu, V. Panin, N. Paul, W. Rodriguez, H. Sakurai, M. Sasano, D. Steppenbeck, L. Stuhl, Y. L. Sun, Y. Togano, T. Uesaka, K. Wimmer, K. Yoneda, O. Aktas, T. Aumann, L. X. Chung, F. Flavigny, S. Franchoo, I. Gasparic, R. B. Gerst, J. Gibelin, K. I. Hahn, D. Kim, T. Koiwai, Y. Kondo, P. Koseoglou, C. Lehr, B. D. Linh, T. Lokotko, M. MacCormick, K. Moschner, T. Nakamura, S. Y. Park, D. Rossi, E. Sahin, P. A. Söderström, D. Sohler, S. Takeuchi, H. Törnqvist, V. Vaquero, V. Wagner, S. Wang, V. Werner, X. Xu, H. Yamada, D. Yan, Z. Yang, M. Yasuda, L. Zanetti

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

5 Scopus citations

Abstract

Gamma decays were observed in ⁵⁶Ca and ⁵⁸Ca following quasi-free one-proton knockout reactions from ^57,59Sc beams at ≈200 MeV/nucleon. For ⁵⁶Ca, a γ ray transition was measured to be 1456(12) keV, while for ⁵⁸Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 2₁⁺→0_gs⁺ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 2₁⁺ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f_5/2 and 0g_9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic ⁶⁰Ca and potentially drives the dripline of Ca isotopes to ⁷⁰Ca or even beyond.

Original language	English
Article number	138025
Journal	Physics Letters B
Volume	843
DOIs	https://doi.org/10.1016/j.physletb.2023.138025
State	Published - Aug 10 2023

Funding

We would like to express our gratitude to the RIKEN Nishina Center accelerator staff for providing the stable and high-intensity primary beam and to the BigRIPS team for operating the secondary beams. S.C. acknowledges the support of the IPA program at RIKEN Nishina Center. F.B. acknowledges the support of the Special Postdoctoral Researcher Program. J.L. acknowledges the support from Research Grants Council (RGC) of Hong Kong with grant of Early Career Scheme ( ECS-27303915 ). K.O. acknowledges the support from JSPS KAKENHI Grants No. JP16K05352 . Y.U. and N.S. acknowledge the support from JSPS KAKENHI Grant No. 20K03981 . Y.L.S. acknowledges the support of the Marie Sk\u0142odowska-Curie Individual Fellowship ( H2020- MSCA-IF-2015-705023 ). V.V. acknowledges support from the Spanish Ministerio de Econom\u00EDa y Competitividad under Contract No. FPA2017-84756-C4-2-P . L.X.C. and B.D.L. would like to thank MOST for its support through the Physics Development Program Grant No. \u0110T\u0110LCN.25/18 . H.N.L. acknowledges the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project No. 279384907- SFB 1245 . I.M. acknowledges the hospitality of RIKEN through the IPA program. R.-B.G. was supported by the Deutsche Forschungsgemeinschaft (DFG) under Grant No. BL 1513/1-1 . D.R. and V. Werner acknowledge the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under grant SFB 1245 . V. Werner and P.K. acknowledge the German BMBF grant number 05P19RDF N1 . P.K. was also supported by HGS-HIRe . D. Sohler was supported by projects GINOP No. GINOP-2.3.3-15-2016-00034 and NKFIH No. NKFIH-K128947 . I.G. was supported by HIC for FAIR and Croatian Science Foundation under projects no. 1257 and 7194 . K.I.H., D.K., and S.Y.P. acknowledge the support from the IBS grant funded by the Korea government (No. IBS-R031-D1 ). This work was also supported by the United Kingdom Science and Technology Facilities Council (STFC) under Grants No. ST/P005314/1 and No. ST/L005816/1 , by JSPS KAKENHI Grant Nos. JP16H02179 and JP18H05404 , and by NKFIH ( 128072 ). The development of MINOS was supported by the European Research Council through the ERC Grant No. MINOS-258567 . J.D.H. acknowledges support from TRIUMF , which receives funding via a contribution through the National Research Council of Canada, NSERC , and S. R. Stroberg for the imsrg++ code [60] used to perform the VS-IMSRG calculations. G.H. and G.R.J. acknowledges support by the US Department of Energy under desc0018223 (NUCLEI SciDAC-4 collaboration) and under Contract No. DE-AC05-00OR22725 with UT-Battelle, LLC (Oak Ridge National Laboratory). Computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research used resources of the Oak Ridge Leadership Computing Facility and of the Compute and Data Environment for Science (CADES) located at Oak Ridge National Laboratory, which is supported by the Office of Science of the Department of Energy under Contract No. DE-AC05-00OR22725. The A3DA calculations were performed on the supercomputer Fugaku at RIKEN AICS and Oakforest-PACS operated by JCAHPC ( hp190160 , hp200130 , hp210165 ). This work was supported in part by MEXT as \u201CPriority Issue on Post-K computer\u201D (Elucidation of the Fundamental Laws and Evolution of the Universe) and \u201CProgram for Promoting Researches on the Supercomputer Fugaku\u201D (Simulation for basic science: from fundamental laws of particles to creation of nuclei) and by JICFuS . This work was supported in part by MEXT KAKENHI Grant No. JP19H05145 .

Funders	Funder number
United Kingdom Science and Technology Facilities Council
Helmholtz International Center for FAIR
H2020 Marie Skłodowska-Curie Actions
Oak Ridge National Laboratory
Data Environment for Science
Ministry of Science and Technology of the People's Republic of China
“Program for Promoting Researches
Natural Sciences and Engineering Research Council of Canada
RIKEN
CADES
TRIUMF
European Research Council
National Research Council Canada
Ministry of Education, Culture, Sports, Science and Technology
Ministerio de Economía y Competitividad	FPA2017-84756-C4-2-P
Ministerio de Economía y Competitividad
U.S. Department of Energy	DE-AC05-00OR22725, desc0018223
U.S. Department of Energy
Office of Science of the Department of Energy	hp190160, hp200130, hp210165
Hrvatska Zaklada za Znanost	IBS-R031-D1, 1257, 7194
Hrvatska Zaklada za Znanost
Horizon 2020 Framework Programme	MSCA-IF-2015-705023
Horizon 2020 Framework Programme
Deutsche Forschungsgemeinschaft	BL 1513/1-1, 279384907- SFB 1245, SFB 1245
Deutsche Forschungsgemeinschaft
Helmholtz Graduate School for Hadron and Ion Research	NKFIH-K128947, GINOP-2.3.3-15-2016-00034
Helmholtz Graduate School for Hadron and Ion Research
Seventh Framework Programme	705023, 258567
Seventh Framework Programme
Research Grants Council, University Grants Committee	ECS-27303915
Research Grants Council, University Grants Committee
Japan Society for the Promotion of Science London	JP16K05352, 20K03981
Japan Society for the Promotion of Science London
Science and Technology Facilities Council	JP16H02179, JP18H05404, ST/L005816/1, 128072, ST/P005314/1
Science and Technology Facilities Council
Joint Institute for Computational Fundamental Science	JP19H05145
Joint Institute for Computational Fundamental Science
Bundesministerium für Bildung und Forschung	05P19RDF N1
Bundesministerium für Bildung und Forschung

Keywords

Shell evolution
γ Ray spectroscopy

Access to Document

10.1016/j.physletb.2023.138025

Cite this

Chen, S., Browne, F., Doornenbal, P., Lee, J., Obertelli, A., Tsunoda, Y., Otsuka, T., Chazono, Y., Hagen, G., Holt, J. D., Jansen, G. R., Ogata, K., Shimizu, N., Utsuno, Y., Yoshida, K., Achouri, N. L., Baba, H., Calvet, D., Château, F., ... Zanetti, L. (2023). Level structures of ^56,58Ca cast doubt on a doubly magic ⁶⁰Ca. Physics Letters B, 843, Article 138025. https://doi.org/10.1016/j.physletb.2023.138025

@article{12f3061be4784cf1acedc73b1a3399ca,

title = "Level structures of 56,58Ca cast doubt on a doubly magic 60Ca",

abstract = "Gamma decays were observed in 56Ca and 58Ca following quasi-free one-proton knockout reactions from 57,59Sc beams at ≈200 MeV/nucleon. For 56Ca, a γ ray transition was measured to be 1456(12) keV, while for 58Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic 60Ca and potentially drives the dripline of Ca isotopes to 70Ca or even beyond.",

keywords = "Shell evolution, γ Ray spectroscopy",

author = "S. Chen and F. Browne and P. Doornenbal and J. Lee and A. Obertelli and Y. Tsunoda and T. Otsuka and Y. Chazono and G. Hagen and Holt, {J. D.} and Jansen, {G. R.} and K. Ogata and N. Shimizu and Y. Utsuno and K. Yoshida and Achouri, {N. L.} and H. Baba and D. Calvet and F. Ch{\^a}teau and N. Chiga and A. Corsi and Cort{\'e}s, {M. L.} and A. Delbart and Gheller, {J. M.} and A. Giganon and A. Gillibert and C. Hilaire and T. Isobe and T. Kobayashi and Y. Kubota and V. Lapoux and Liu, {H. N.} and T. Motobayashi and I. Murray and H. Otsu and V. Panin and N. Paul and W. Rodriguez and H. Sakurai and M. Sasano and D. Steppenbeck and L. Stuhl and Sun, {Y. L.} and Y. Togano and T. Uesaka and K. Wimmer and K. Yoneda and O. Aktas and T. Aumann and Chung, {L. X.} and F. Flavigny and S. Franchoo and I. Gasparic and Gerst, {R. B.} and J. Gibelin and Hahn, {K. I.} and D. Kim and T. Koiwai and Y. Kondo and P. Koseoglou and C. Lehr and Linh, {B. D.} and T. Lokotko and M. MacCormick and K. Moschner and T. Nakamura and Park, {S. Y.} and D. Rossi and E. Sahin and S{\"o}derstr{\"o}m, {P. A.} and D. Sohler and S. Takeuchi and H. T{\"o}rnqvist and V. Vaquero and V. Wagner and S. Wang and V. Werner and X. Xu and H. Yamada and D. Yan and Z. Yang and M. Yasuda and L. Zanetti",

note = "Publisher Copyright: {\textcopyright} 2023 The Author(s)",

year = "2023",

month = aug,

day = "10",

doi = "10.1016/j.physletb.2023.138025",

language = "English",

volume = "843",

journal = "Physics Letters B",

issn = "0370-2693",

publisher = "Elsevier",

}

Chen, S, Browne, F, Doornenbal, P, Lee, J, Obertelli, A, Tsunoda, Y, Otsuka, T, Chazono, Y, Hagen, G, Holt, JD, Jansen, GR, Ogata, K, Shimizu, N, Utsuno, Y, Yoshida, K, Achouri, NL, Baba, H, Calvet, D, Château, F, Chiga, N, Corsi, A, Cortés, ML, Delbart, A, Gheller, JM, Giganon, A, Gillibert, A, Hilaire, C, Isobe, T, Kobayashi, T, Kubota, Y, Lapoux, V, Liu, HN, Motobayashi, T, Murray, I, Otsu, H, Panin, V, Paul, N, Rodriguez, W, Sakurai, H, Sasano, M, Steppenbeck, D, Stuhl, L, Sun, YL, Togano, Y, Uesaka, T, Wimmer, K, Yoneda, K, Aktas, O, Aumann, T, Chung, LX, Flavigny, F, Franchoo, S, Gasparic, I, Gerst, RB, Gibelin, J, Hahn, KI, Kim, D, Koiwai, T, Kondo, Y, Koseoglou, P, Lehr, C, Linh, BD, Lokotko, T, MacCormick, M, Moschner, K, Nakamura, T, Park, SY, Rossi, D, Sahin, E, Söderström, PA, Sohler, D, Takeuchi, S, Törnqvist, H, Vaquero, V, Wagner, V, Wang, S, Werner, V, Xu, X, Yamada, H, Yan, D, Yang, Z, Yasuda, M & Zanetti, L 2023, 'Level structures of ^56,58Ca cast doubt on a doubly magic ⁶⁰Ca', Physics Letters B, vol. 843, 138025. https://doi.org/10.1016/j.physletb.2023.138025

TY - JOUR

T1 - Level structures of 56,58Ca cast doubt on a doubly magic 60Ca

AU - Chen, S.

AU - Browne, F.

AU - Doornenbal, P.

AU - Lee, J.

AU - Obertelli, A.

AU - Tsunoda, Y.

AU - Otsuka, T.

AU - Chazono, Y.

AU - Hagen, G.

AU - Holt, J. D.

AU - Jansen, G. R.

AU - Ogata, K.

AU - Shimizu, N.

AU - Utsuno, Y.

AU - Yoshida, K.

AU - Achouri, N. L.

AU - Baba, H.

AU - Calvet, D.

AU - Château, F.

AU - Chiga, N.

AU - Corsi, A.

AU - Cortés, M. L.

AU - Delbart, A.

AU - Gheller, J. M.

AU - Giganon, A.

AU - Gillibert, A.

AU - Hilaire, C.

AU - Isobe, T.

AU - Kobayashi, T.

AU - Kubota, Y.

AU - Lapoux, V.

AU - Liu, H. N.

AU - Motobayashi, T.

AU - Murray, I.

AU - Otsu, H.

AU - Panin, V.

AU - Paul, N.

AU - Rodriguez, W.

AU - Sakurai, H.

AU - Sasano, M.

AU - Steppenbeck, D.

AU - Stuhl, L.

AU - Sun, Y. L.

AU - Togano, Y.

AU - Uesaka, T.

AU - Wimmer, K.

AU - Yoneda, K.

AU - Aktas, O.

AU - Aumann, T.

AU - Chung, L. X.

AU - Flavigny, F.

AU - Franchoo, S.

AU - Gasparic, I.

AU - Gerst, R. B.

AU - Gibelin, J.

AU - Hahn, K. I.

AU - Kim, D.

AU - Koiwai, T.

AU - Kondo, Y.

AU - Koseoglou, P.

AU - Lehr, C.

AU - Linh, B. D.

AU - Lokotko, T.

AU - MacCormick, M.

AU - Moschner, K.

AU - Nakamura, T.

AU - Park, S. Y.

AU - Rossi, D.

AU - Sahin, E.

AU - Söderström, P. A.

AU - Sohler, D.

AU - Takeuchi, S.

AU - Törnqvist, H.

AU - Vaquero, V.

AU - Wagner, V.

AU - Wang, S.

AU - Werner, V.

AU - Xu, X.

AU - Yamada, H.

AU - Yan, D.

AU - Yang, Z.

AU - Yasuda, M.

AU - Zanetti, L.

PY - 2023/8/10

Y1 - 2023/8/10

N2 - Gamma decays were observed in 56Ca and 58Ca following quasi-free one-proton knockout reactions from 57,59Sc beams at ≈200 MeV/nucleon. For 56Ca, a γ ray transition was measured to be 1456(12) keV, while for 58Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic 60Ca and potentially drives the dripline of Ca isotopes to 70Ca or even beyond.

AB - Gamma decays were observed in 56Ca and 58Ca following quasi-free one-proton knockout reactions from 57,59Sc beams at ≈200 MeV/nucleon. For 56Ca, a γ ray transition was measured to be 1456(12) keV, while for 58Ca an indication for a transition was observed at 1115(34) keV. Both transitions were tentatively assigned as the 21+→0gs+ decays, and were compared to results from ab initio and conventional shell-model approaches. A shell-model calculation in a wide model space with a marginally modified effective nucleon-nucleon interaction depicts excellent agreement with experiment for 21+ level energies, two-neutron separation energies, and reaction cross sections, corroborating the formation of a new nuclear shell above the N = 34 shell. Its constituents, the 0f5/2 and 0g9/2 orbitals, are almost degenerate. This degeneracy precludes the possibility for a doubly magic 60Ca and potentially drives the dripline of Ca isotopes to 70Ca or even beyond.

KW - Shell evolution

KW - γ Ray spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=85163193865&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2023.138025

DO - 10.1016/j.physletb.2023.138025

M3 - Article

AN - SCOPUS:85163193865

SN - 0370-2693

VL - 843

JO - Physics Letters B

JF - Physics Letters B

M1 - 138025

ER -