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DOE OSTI Β· 3412368

Observing neutron alignment at high angular momenta in heavy deformed actinides

Chowdhury, Partha [University of Massachusetts, Lowell, MA (United States)] (ORCID:0000000280158988)Β·Khoo, T. L. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:000000024352060X)Β·Hota, S. S. [University of Massachusetts, Lowell, MA (United States)] (ORCID:0000000335799900)Β·Qiu, Y. [University of Massachusetts, Lowell, MA (United States)]Β·Lister, C. J. [University of Massachusetts, Lowell, MA (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000213874175)Β·Carpenter, M. P. [Argonne National Laboratory (ANL), Argonne, IL (United States)]Β·Frauendorf, S. [University of Notre Dame, IN (United States)] (ORCID:0000000346274368)Β·Janssens, R. V. F. [University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000170951715)Β·Kondev, F. G. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000295675785)Β·Lauritsen, T. [Argonne National Laboratory (ANL), Argonne, IL (United States)]Β·Seweryniak, D. [Argonne National Laboratory (ANL), Argonne, IL (United States)]
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Abstract

An outstanding puzzle in the structure of very heavy nuclei lies in the rotation response of deformed transuranic isotopes. While the rotation alignment of pairs of 𝑖 13/2 protons is ubiquitous and well understood, observing the analogous alignment of the 𝑗 15/2 neutrons has been elusive. In this work we present a new quantitative analysis approach: from their moments of inertia as a function of frequency, we compare the alignments of rotational bands with both β€œlow” and high-𝑗 intrinsic structures in the 𝑁 = 151 isotones of Pu, Cm, Cf, and No, thereby distinguishing between the alignments of neutron versus proton pairs through β€œblocking” effects. In this way, the alignment of 𝑗 15/2 neutrons can be clearly identified for the first time. The protons and neutrons begin aligning at a very similar frequency. The contribution of 𝑗 15/2 neutrons to the total alignment is found to grow with increasing 𝑍 compared to 𝑖 13/2 protons. To explain these observations, it is necessary to adopt a self-consistent set of single-particle energies corresponding to the nuclear shape that minimizes the mass. The shape description needs to include high-order deformations up to at least 𝛽 6 .

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Chowdhury, Partha [University of Massachusetts, Lowell, MA (United States)] (ORCID:0000000280158988), Khoo, T. L. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:000000024352060X), Hota, S. S. [University of Massachusetts, Lowell, MA (United States)] (ORCID:0000000335799900), Qiu, Y. [University of Massachusetts, Lowell, MA (United States)], Lister, C. J. [University of Massachusetts, Lowell, MA (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States)] (ORCID:0000000213874175), Carpenter, M. P. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Frauendorf, S. [University of Notre Dame, IN (United States)] (ORCID:0000000346274368), Janssens, R. V. F. [University of North Carolina at Chapel Hill, NC (United States); Duke University, Durham, NC (United States)] (ORCID:0000000170951715), Kondev, F. G. [Argonne National Laboratory (ANL), Argonne, IL (United States)] (ORCID:0000000295675785), Lauritsen, T. [Argonne National Laboratory (ANL), Argonne, IL (United States)], Seweryniak, D. [Argonne National Laboratory (ANL), Argonne, IL (United States)]. 2026-08-12. Observing neutron alignment at high angular momenta in heavy deformed actinides. https://doi.org/10.1103/9md2-9scj

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