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DOE OSTI · 3003133

Triaxiality and shape dynamics in 70 Ge

Kowalewski, Tyler M. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000174931842)·Ayangeakaa, A. D. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000316793175)·Sensharma, N. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000250469451)·Janssens, R. V. F. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000170951715)·Wang, Y. M. [East China Normal University, Shanghai (China)] (ORCID:0009000187266324)·Chen, Q. B. [East China Normal University, Shanghai (China)] (ORCID:0000000151594468)·Allmond, James M. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000165338721)·Campbell, C. M. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000335774316)·Carmichael, S. [University of Notre Dame, IN (United States)] (ORCID:0000000274541876)·Carpenter, M. P. [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Copp, P. [Argonne National Laboratory (ANL), Argonne, IL (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)]·Cousins, C. [University of Surrey (United Kingdom)]·Devlin, M. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000269482154)·Garg, U. [University of Notre Dame, IN (United States)] (ORCID:0000000187514204)·Müller-Gatermann, C. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000291815568)·Gray, Tim J. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)] (ORCID:0000000339656130)·Hartley, D. J. [United States Naval Academy, Annapolis, MD (United States)] (ORCID:0000000162956815)·Heery, J. [University of Surrey (United Kingdom)] (ORCID:0000000230239907)·Henderson, J. [University of Surrey (United Kingdom)] (ORCID:0000000260109644)·Jayatissa, H. [Argonne National Laboratory (ANL), Argonne, IL (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)]·Johnson, S. R. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0009000434405070)·Kisyov, S. P. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000247187744)·Kondev, F. G. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000295675785)·Lauritsen, T. [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Nandi, S. [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Rathod, R. [University of Notre Dame, IN (United States)] (ORCID:0009000435704937)·Reviol, W. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000253727743)·Rocchini, M. [University of Guelph, ON (Canada); INFN Sezione di Firenze (Italy)] (ORCID:0000000168690181)·Rubino, E. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000264227015)·Russell, R. [University of Surrey (United Kingdom)] (ORCID:0000000165800111)·Saracino, A. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0009000203572429)·Seweryniak, D. [Argonne National Laboratory (ANL), Argonne, IL (United States)]·Siciliano, M. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000245980298)·Wu, C. Y. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000157727196)
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Abstract

The electromagnetic properties of low-lying states in 70 Ge were investigated via multi-step Coulomb excitation of a 70 Ge beam impinging on a 208 Pb target at the ATLAS facility of the Argonne National Laboratory. A total of 27 transitional elements and six diagonal matrix elements coupling 11 low-lying states, were extracted from the measured cross sections. These were used to calculate reduced transition probabilities, spectroscopic quadrupole moments, and rotational invariant shape parameters, providing enhanced precision and expanding on previous studies. The experimental data were compared within several theoretical frameworks, including the generalized triaxial rotor model, configuration interaction shell-model calculations, and computations within the combined frameworks of relativistic density functional theory and the five-dimensional collective Hamiltonian. The results demonstrate a good agreement with the experimental data and, in conjunction with calculations using a two-state mixing model, support significant triaxiality and strong mixing between the 0$^{+}_{1}$ and 0$^{+}_{2}$ states. This results in the magnitudes of their respective quadrupole deformations [β rms (0$^{+}_{1}$) = 0.228 (3), β rms (0$^{+}_{2}$) = 0.273 (1)] being more similar than previously observed. Furthermore, the implications of these results for understanding the complex shape coexistence phenomena, the role of triaxiality, and shape evolution along the Ge isotopic chain are discussed.

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59 ≤ A ≤ 89Collective modelsCoulomb excitationNuclear reactionsNuclear shapes and momentsNuclear structure & decaysNucleon distributionShell modelcollective modelsnuclear decaysnuclear momentsnuclear reactionsnuclear shapesnuclear structurenucleon distributionshell model

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Kowalewski, Tyler M. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000174931842), Ayangeakaa, A. D. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000316793175), Sensharma, N. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000250469451), Janssens, R. V. F. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000170951715), Wang, Y. M. [East China Normal University, Shanghai (China)] (ORCID:0009000187266324), Chen, Q. B. [East China Normal University, Shanghai (China)] (ORCID:0000000151594468), Allmond, James M. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000165338721), Campbell, C. M. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000335774316), Carmichael, S. [University of Notre Dame, IN (United States)] (ORCID:0000000274541876), Carpenter, M. P. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Copp, P. [Argonne National Laboratory (ANL), Argonne, IL (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)], Cousins, C. [University of Surrey (United Kingdom)], Devlin, M. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)] (ORCID:0000000269482154), Garg, U. [University of Notre Dame, IN (United States)] (ORCID:0000000187514204), Müller-Gatermann, C. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000291815568), Gray, Tim J. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States)] (ORCID:0000000339656130), Hartley, D. J. [United States Naval Academy, Annapolis, MD (United States)] (ORCID:0000000162956815), Heery, J. [University of Surrey (United Kingdom)] (ORCID:0000000230239907), Henderson, J. [University of Surrey (United Kingdom)] (ORCID:0000000260109644), Jayatissa, H. [Argonne National Laboratory (ANL), Argonne, IL (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)], Johnson, S. R. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0009000434405070), Kisyov, S. P. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)] (ORCID:0000000247187744), Kondev, F. G. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000295675785), Lauritsen, T. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Nandi, S. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Rathod, R. [University of Notre Dame, IN (United States)] (ORCID:0009000435704937), Reviol, W. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000253727743), Rocchini, M. [University of Guelph, ON (Canada); INFN Sezione di Firenze (Italy)] (ORCID:0000000168690181), Rubino, E. [Michigan State University, East Lansing, MI (United States)] (ORCID:0000000264227015), Russell, R. [University of Surrey (United Kingdom)] (ORCID:0000000165800111), Saracino, A. [The University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0009000203572429), Seweryniak, D. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Siciliano, M. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000245980298), Wu, C. Y. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000157727196). 2025-09-25. Triaxiality and shape dynamics in 70 Ge. https://doi.org/10.1103/cmks-jst1

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