Identification of a universal three-body s-wave resonance in 10He.

White Rose Research Online (University of Leeds, The University of Sheffield, University of York) 2026-12-01 added 2026-07-23

Y Kikuchi, A Corsi, Y Kubota, M Gómez-Ramos, S Endo, G Authelet, H Baba, C Caesar, D Calvet, A Delbart, M Dozono, F Flavigny, J -M Gheller, J Gibelin, A Giganon, A Gillibert, S Giraud, K Hasegawa, T Isobe, Y Kanaya, S Kawakami, Y Kiyokawa, M Kobayashi, N Kobayashi, T Kobayashi, Y Kondo, Z Korkulu, S Koyama, V Lapoux, Y Maeda, F M Marqués, T Miyazaki, T Motobayashi, T Nakamura, N Nakatsuka, Y Nishio, A Obertelli, A Ohkura, N A Orr, S Ota, H Otsu, T Ozaki, V Panin, S Paschalis, E C Pollacco, S Reichert, J -Y Roussé, A T Saito, S Sakaguchi, M Sako, C Santamaria, M Sasano, H Sato, M Shikata, Y Shimizu, Y Shindo, L Stuhl, T Sumikama, M Tabata, Y Togano, J Tsubota, J Yasuda, K Yoneda, J Zenihiro, T Uesaka

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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.