Extended p3/2 Neutron Orbital and the N=32 Shell Closure in Ca 52

• Published in: Physical review letters
• Main Authors: Enciu, M, Liu, H.N, Obertelli, A, Doornenbal, P, Nowacki, F, Ogata, K, Poves, A, Yoshida, K, Achouri, N.L, Baba, H, Browne, F, Calvet, D, Château, F, Chen, S, Chiga, N, Corsi, A, Cortés, M.L, Delbart, A, Gheller, J.-M, Giganon, A, Gillibert, A, Hilaire, C, Isobe, T, Kobayashi, T, Kubota, Y, Lapoux, V, Motobayashi, T, Murray, I, Otsu, H, Panin, V, Paul, N, Rodriguez, W, Sakurai, H, Sasano, M, Steppenbeck, D, Stuhl, L, Sun, Y.L, Togano, Y, Uesaka, T, Wimmer, K, Yoneda, K, Aktas, O, Aumann, T, Chung, L.X, Flavigny, F, Franchoo, S, Gasparic, I, Gerst, R.-B, Gibelin, J, Hahn, K.I, Kim, D, Kondo, Y, Koseoglou, P, Lee, J, Lehr, C, Li, P.J, Linh, B.D, Lokotko, T, Maccormick, M, Moschner, K, Nakamura, T, Park, S.Y, Rossi, D, Sahin, Eda, Söderström, P.-A, Sohler, D, Takeuchi, S, Toernqvist, H, Vaquero, V, Wagner, V, Wang, S, Werner, V, Xu, X, Yamada, H, Yan, D, Yang, Z, Yasuda, M, Zanetti, L
• Format: Journal Article
• Language: English; Norwegian
• Published: American Physical Society 23-12-2022
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.129.262501

The one-neutron knockout from 52Ca in inverse kinematics onto a proton target was performed at ∼230  MeV/nucleon combined with prompt γ spectroscopy. Exclusive quasifree scattering cross sections to bound states in 51Ca and the momentum distributions corresponding to the removal of 1f7/2 and 2p3/2 neutrons were measured. The cross sections, interpreted within the distorted-wave impulse approximation reaction framework, are consistent with a shell closure at the neutron number N=32, found as strong as at N=28 and N=34 in Ca isotopes from the same observables. The analysis of the momentum distributions leads to a difference of the root-mean-square radii of the neutron 1f7/2 and 2p3/2 orbitals of 0.61(23) fm, in agreement with the modified-shell-model prediction of 0.7 fm suggesting that the large root-mean-square radius of the 2p3/2 orbital in neutron-rich Ca isotopes is responsible for the unexpected linear increase of the charge radius with the neutron number.