New $α$-Emitting Isotope $^{214}$U and Abnormal Enhancement of $α$-Particle Clustering in Lightest Uranium Isotopes

Z. Y. Zhang; H. B. Yang; M. H. Huang; Z. G. Gan; C. X. Yuan; C. Qi; A. N. Andreyev; M. L. Liu; L. Ma; M. M. Zhang; Y. L. Tian; Y. S. Wang; J. G. Wang; C. L. Yang; G. S. Li; Y. H. Qiang; W. Q. Yang; R. F. Chen; H. B. Zhang; Z. W. Lu; X. X. Xu; L. M. Duan; H. R. Yang; W. X. Huang; Z. Liu; X. H. Zhou; Y. H. Zhang; H. S. Xu; N. Wang; H. B. Zhou; X. J. Wen; S. Huang; W. Hua; L. Zhu; X. Wang; Y. C. Mao; X. T. He; S. Y. Wang; W. Z. Xu; H. W. Li; Z. Z. Ren; S. G. Zhou

doi:10.1103/physrevlett.126.152502

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arXiv · 2101.06023

New $α$-Emitting Isotope $^{214}$U and Abnormal Enhancement of $α$-Particle Clustering in Lightest Uranium Isotopes

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Abstract

A new $α$-emitting isotope $^{214}$U, produced by fusion-evaporation reaction $^{182}$W($^{36}$Ar, 4n)$^{214}$U, was identified by employing the gas-filled recoil separator SHANS and recoil-$α$ correlation technique. More precise $α$-decay properties of even-even nuclei $^{216,218}$U were also measured in reactions of $^{40}$Ar, $^{40}$Ca with $^{180, 182, 184}$W targets. By combining the experimental data, improved $α$-decay reduced widths $δ^2$ for the even-even Po--Pu nuclei in the vicinity of magic neutron number $N=126$ were deduced. Their systematic trends are discussed in terms of $N_{p}N_{n}$ scheme in order to study the influence of proton-neutron interaction on $α$ decay in this region of nuclei. It is strikingly found that the reduced widths of $^{214,216}$U are significantly enhanced by a factor of two as compared with the $N_{p}N_{n}$ systematics for the $84 \leq Z \leq 90$ and $N<126$ even-even nuclei. The abnormal enhancement is interpreted by the strong monopole interaction between the valence protons and neutrons occupying the $π1f_{7/2}$ and $ν1f_{5/2}$ spin-orbit partner orbits, which is supported by a large-scale shell model calculation.

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Z. Y. Zhang, H. B. Yang, M. H. Huang, Z. G. Gan, C. X. Yuan, C. Qi, A. N. Andreyev, M. L. Liu, L. Ma, M. M. Zhang, Y. L. Tian, Y. S. Wang, J. G. Wang, C. L. Yang, G. S. Li, Y. H. Qiang, W. Q. Yang, R. F. Chen, H. B. Zhang, Z. W. Lu, X. X. Xu, L. M. Duan, H. R. Yang, W. X. Huang, Z. Liu, X. H. Zhou, Y. H. Zhang, H. S. Xu, N. Wang, H. B. Zhou, X. J. Wen, S. Huang, W. Hua, L. Zhu, X. Wang, Y. C. Mao, X. T. He, S. Y. Wang, W. Z. Xu, H. W. Li, Z. Z. Ren, S. G. Zhou. 2021-01-15. New $α$-Emitting Isotope $^{214}$U and Abnormal Enhancement of $α$-Particle Clustering in Lightest Uranium Isotopes. https://doi.org/10.1103/physrevlett.126.152502

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