Direct observation of three-neutron emission from He * 7 and the search for the trineutron

Physical Review Research 2026 Open access

Read full text
Authors: S.W. Huang, C. Lenain, Z. Yang, F. M. Marqués, J. Gibelin, J. G. Li, A. Matta, Nigel A. Orr, Lynda Achouri, D.S. Ahn, A. Anne, T. Aumann
+88 more H. Baba, D. Beaumel, M. Böhmer, K. Boretzky, M. Caamaño, N. Chen, S. Chen, N. Chiga, M. L. Cortés, D. Cortina, P. Doornenbal, C. A. Douma, F. Dufter, J. Feng, Beatriz Fernández-Domínguez, Z. Elekes, U. Forsberg, T. Fujino, N. Fukuda, I. Gašparić, Z. Ge, R. Gernhäuser, J. -M. Gheller, A. Gillibert, Z. Halász, T. Harada, Muhsin N. Harakeh, A. Hirayama, N. Inabe, T. Isobe, J. Kahlbow, Nasser Kalantar-Nayestanaki, D. Kim, S. Kim, S. Kiyotake, T. Kobayashi, D. Koerper, Y. Kondo, P. Koseoglou, Y. Kubota, I. Kuti, C. Lehr, P. J. Li, Y. Liu, Yukie Maeda, S. Masuoka, M. Matsumoto, Jan Mayer, N. Michel, H. Miki, M. Miwa, B. Monteagudo, I. Murray, T. Nakamura, A. Obertelli, H. Otsu, V. Panin, S. Park, M. Pârlog, S. Paschalis, M. Potlog, S. Reichert, A. Revel, Dominic M. Rossi, A. T. Saito, M. Sasano, Hiromi Sato, H. Scheit, F. Schindler, T. Shimada, Y. Shimizu, S. Shimoura, H. Simon, I. Stefan, S. Storck, L. Stuhl, H. Suzuki, D. Symochko, H. Takeda, S. Takeuchi, Junki Tanaka, Y. Togano, T. Tomai, H. Törnqvist, E. Tronchin, J. Tscheuschner, V. Wagner, Kathrin Wimmer
DOI: 10.1103/sr8h-2n6v
Cited by: 1
References: 91

Abstract

Three-neutron emission from He 7 has been directly measured for the first time, following neutron knockout from a He 8 beam at 156 MeV/nucleon. A resonancelike structure at 2.08(4) MeV above the He 4 + 3 n threshold [ E x = 2.68 ( 4 ) MeV] with a width of 3.9(2) MeV was observed and deduced to arise predominately from the predicted J π = 3 / 2 2 − level. The three-neutron invariant-mass spectrum was reconstructed and found to peak at around 1 MeV and could, through complete simulations incorporating neutron-neutron correlations, be very well described by the sequential decay of He * 7 via the 2 1 + excited state of He 6 . No evidence was found for any significant three-neutron correlations beyond those expected from well-established two-body interactions, including a trineutron resonance.

Fields of Study & Subjects

Dark Matter and Cosmic Phenomena Quantum Chromodynamics and Particle Interactions Neutrino Physics Research

Publication details

Journal / source
Physical Review Research
Publisher
American Physical Society (APS)
Volume
8
Issue
2
Pages
L022003
Publication date
10 February 2026
Language
EN