Phys.Rev.Lett. 132, 082501 (2024)

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

Mass, Spectroscopy, and Two-Neutron Decay of ¹⁶Be

RADIOACTIVITY ¹⁶Be(2n) [from ¹H(¹⁷B, 2p), E=277 MeV/nucleon]; measured decay products, En, In; deduced resonance energies, J, π, Q-value. Comparison with calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component. The 15 cm thick liquid hydrogen target of MINOS, the BigRIPS fragment separator, the Radioactive Isotope Beam Factory of the RIKEN Nishina Center.

doi: 10.1103/PhysRevLett.132.082501