Low-lying single-particle structure of 17C and the N = 14 sub-shell closure

• Published in: Physics letters. B 2020-12, Vol.811 (C), p.135939, Article 135939
• Main Authors: Pereira-López, X., Fernández-Domínguez, B., Delaunay, F., Achouri, N.L., Orr, N.A., Catford, W.N., Assié, M., Bailey, S., Bastin, B., Blumenfeld, Y., Borcea, R., Caamaño, M., Caceres, L., Clément, E., Corsi, A., Curtis, N., Deshayes, Q., Farget, F., Fisichella, M., de France, G., Franchoo, S., Freer, M., Gibelin, J., Gillibert, A., Grinyer, G.F., Hammache, F., Kamalou, O., Knapton, A., Kokalova, T., Lapoux, V., Lay, J.A., Le Crom, B., Leblond, S., Lois-Fuentes, J., Marqués, F.M., Matta, A., Morfouace, P., Moro, A.M., Otsuka, T., Pancin, J., Perrot, L., Piot, J., Pollacco, E., Ramos, D., Rodríguez-Tajes, C., Roger, T., Rotaru, F., Sénoville, M., de Séréville, N., Smith, R., Sorlin, O., Stanoiu, M., Stefan, I., Stodel, C., Suzuki, D., Suzuki, T., Thomas, J.C., Timofeyuk, N., Vandebrouck, M., Walshe, J., Wheldon, C.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2020.135939

The first investigation of the single-particle structure of the bound states of 17C, via the d(16C,p) transfer reaction, has been undertaken. The measured angular distributions confirm the spin-parity assignments of 1/2+ and 5/2+ for the excited states located at 217 and 335 keV, respectively. The spectroscopic factors deduced for these states exhibit a marked single-particle character, in agreement with shell model and particle-core model calculations, and combined with their near degeneracy in energy provide clear evidence for the absence of the N=14 sub-shell closure. The very small spectroscopic factor found for the 3/2+ ground state is consistent with theoretical predictions and indicates that the ν1d3/2 strength is carried by unbound states. With a dominant ℓ=0 valence neutron configuration and a very low separation energy, the 1/2+ excited state is a one-neutron halo candidate.