Phys.Lett. B 843, 138025 (2023)

S.Chen, F.Browne, P.Doornenbal, J.Lee, A.Obertelli, Y.Tsunoda, T.Otsuka, Y.Chazono, G.Hagen, J.D.Holt, G.R.Jansen, K.Ogata, N.Shimizu, Y.Utsuno, K.Yoshida, N.L.Achouri, H.Baba, D.Calvet, F.Chateau, N.Chiga, A.Corsi, M.L.Cortes, A.Delbart, J.-M.Gheller, A.Giganon, A.Gillibert, C.Hilaire, T.Isobe, T.Kobayashi, Y.Kubota, V.Lapoux, H.N.Liu, T.Motobayashi, I.Murray, H.Otsu, V.Panin, N.Paul, W.Rodriguez, H.Sakurai, M.Sasano, D.Steppenbeck, L.Stuhl, Y.L.Sun, Y.Togano, T.Uesaka, K.Wimmer, K.Yoneda, O.Aktas, T.Aumann, L.X.Chung, F.Flavigny, S.Franchoo, I.Gasparic, R.-B.Gerst, J.Gibelin, K.I.Hahn, D.Kim, T.Koiwai, Y.Kondo, P.Koseoglou, C.Lehr, B.D.Linh, T.Lokotko, M.MacCormick, K.Moschner, T.Nakamura, S.Y.Park, D.Rossi, E.Sahin, P.-A.Soderstrom, D.Sohler, S.Takeuchi, H.Tornqvist, V.Vaquero, V.Wagner, S.Wang, V.Werner, X.Xu, H.Yamada, D.Yan, Z.Yang, M.Yasuda, L.Zanetti

Level structures of ^{56, 58}Ca cast doubt on a doubly magic ⁶⁰Ca

NUCLEAR REACTIONS ¹H(⁵⁷Sc, 2p)⁵⁶Ca, E=209 MeV/nucleon; ¹H(⁵⁹Sc, 2p)⁵⁸Ca, E=199 MeV/nucleon, [^57,59Sc secondary beams from ⁹Be(⁷⁰Zn, X), E=345 MeV/nucleon, followed by separation and identification of ions of interest using the BigRIPS separator at RIBF-RIKEN facility]; measured reaction residues of ⁵⁶Ca and ⁵⁸Ca through identification by the SAMURAI spectrometer, Doppler-corrected Eγ, Iγ, (particle)γ-coin using the DALI2⁺ array using MINOS liquid hydrogen target. ^56,58Ca; deduced energies of the first 2+ levels. Comparison with shell-model calculations with the GXPF1B Hamiltonian in full pf model space, and the state-of-the-art ab initio approaches: VS-IMSRG method, and CC calculations. Systematics of energies of the first 2+ states and S(2n) from experiment (N=22-36) and theory in N=22-54 Ca isotopes.

doi: 10.1016/j.physletb.2023.138025