Abstract
Universality in physics describes the emergence of common features in vastly different systems. One fascinating example is the Efimov phenomenon where three-body resonantly interacting systems display universal properties. Efimov states have been observed in ultra-cold-atom systems, but their manifestation in nuclei remains elusive due to the long-range repulsive Coulomb interaction and the stringent requirement for at least two s-wave resonances in its subsystems. Recent theories propose another universality in three-body halos with only one s-wave resonance. Here, we report the identification of a precursor of this phenomenon in a neutron-rich 10He nucleus. With higher statistics and better sensitivities than previous experiments, we identify two low-lying 0+ states of 10He at ~ 1 MeV and ~ 2 MeV above its two-neutron decay threshold, and determine an s-wave scattering length of ~ − 3.5 fm between 8He and neutron. It is revealed that the lower energy state, the ground state of 10He, is a three-body state with only s-wave interactions among its subsystems. This state manifests as a resonance structure, which is a direct consequence of a universal long-range three-body repulsion. Our work sheds new light on quantum halos with finite lifetimes, providing a path toward their unified understanding across various scales and fields.
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Our unpublished computer codes used to generate the results reported in this paper are available from the corresponding author on request.
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Acknowledgements
We are very grateful to the RIKEN Nishina Center accelerator staff for providing the stable and high-intensity 48Ca beam and to the BigRIPS team for the smooth operation of the secondary beam. Y.L.S. acknowledges financial support by the Fundamental Research Funds for the Central Universities and by the National Natural Science Foundation of China (grant no. 12575121). Y.L.S., A. Obertelli acknowledge the support from the Alexander von Humboldt foundation. M.G.-R. acknowledges financial support by MCIN/AEI/10.13039/501100011033 under grant IJC2020-043878-I (also funded by “European Union NextGenerationEU/PRTR”) and under I+D+i project no. PID2020-114687GB-I00. T.U., J.Z. acknowledge support from the Grants-in-Aid of the Japan Society for the Promotion of Science (grant no. JP21H04975). T.N. acknowledges the support of JSPS KAKENHI grants nos. JP18H05404 and JP24H00006. J.G., F.M.M., and N.A.O. acknowledge partial support from the Franco-Japanese LIA-International Associated Laboratory for Nuclear Structure Problems as well as the French ANR-14-CE33-0022-02 EXPAND. S.E. acknowledges the support of Matsuo Foundation and JSPS KAKENHI grants no. JP25K00217. This work was supported by project code IBS-R031-D1. Z.H.Y. acknowledges support from the National Key R&D Program of China (Grant No. 2023YFE0101500). This work was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. RS-2024-00436392). The development of MINOS was supported by the European Research Council through the ERC Grant No. MINOS-258567. We thank G.V. Rogachev and H.-W. Hammer for the valuable discussions and for the comments on the manuscript. Y.L.S. acknowledges valuable discussions with I. Tanihata, S.M. Wang, and C.X. Yuan.
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Y.L.S. performed the offline analysis and drafted the manuscript based on discussions with T.U., Y. Kikuchi, and S.E. A.C., Y. Kubota are spokespersons for the experiment. Y.L.S., T.U. proposed the data analysis of the 10He channel. Y. Kikuchi, S.E. performed the theoretical calculations presented in the main text. M.G.-R. performed the QTC calculations. S.E. made the deduction of the effective angular momentum. A.C., Y. Kubota, G.A., H.B., C.C., D.C., A.D., M.D., J.F., F.F., J.-M.G., J.G., A. Giganon, A. Gillibert, S.G., K.H., T.I., Y. Kanaya, S. Kawakami, D.K., Y. Kiyokawa, M.K., N.K., T.K.,Y. Kondo, Z.K., S. Koyama, V.L., Y.M., F.M.M., T. Miyazaki, T. Motobayashi, T.N., N.N., Y.N., A. Obertelli, A. Ohkura, N.A.O., S.O., H.O., T.O., V.P., S.P., E.C.P., S.R., J.-Y. R., A.T.S., S.S., M.S., C.S., M. Sasano, H.S., M. Shikata, Y. Shimizu, Y. Shindo, L.S., T.S., M.T., Y.T., J.T., Z.H.Y., J.Y., K.Y., J.Z., and T.U. took part in the setting up of the experiment and/or monitored the data accumulation and/or maintained the operation of the experiment and detectors. All authors read, commented on and approved the manuscript.
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Sun, Y.L., Kikuchi, Y., Corsi, A. et al. Identification of a universal three-body s-wave resonance in 10He. Nat Commun (2026). https://doi.org/10.1038/s41467-026-71138-z
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DOI: https://doi.org/10.1038/s41467-026-71138-z
