Neutron-proton pairing in the N=Z radioactive fp-shell nuclei 56Ni and 52Fe probed by pair transfer

oleh: B. Le Crom, M. Assié, Y. Blumenfeld, J. Guillot, H. Sagawa, T. Suzuki, M. Honma, N.L. Achouri, B. Bastin, R. Borcea, W.N. Catford, E. Clément, L. Cáceres, M. Caamaño, A. Corsi, G. De France, F. Delaunay, N. De Séréville, B. Fernandez-Dominguez, M. Fisichella, S. Franchoo, A. Georgiadou, J. Gibelin, A. Gillibert, F. Hammache, O. Kamalou, A. Knapton, V. Lapoux, S. Leblond, A.O. Macchiavelli, F.M. Marqués, A. Matta, L. Ménager, P. Morfouace, N.A. Orr, J. Pancin, X. Pereira-Lopez, L. Perrot, J. Piot, E. Pollacco, D. Ramos, T. Roger, F. Rotaru, A.M. Sánchez-Benítez, M. Sénoville, O. Sorlin, M. Stanoiu, I. Stefan, C. Stodel, D. Suzuki, J.-C. Thomas, M. Vandebrouck

Format: Article
Diterbitkan: Elsevier 2022-06-01

Deskripsi

The isovector and isoscalar components of neutron-proton pairing are investigated in the N=Z unstable nuclei of the fp-shell through the two-nucleon transfer reaction (p,3He) in inverse kinematics. The combination of particle and gamma-ray detection with radioactive beams of 56Ni and 52Fe, produced by fragmentation at the GANIL/LISE facility, made it possible to carry out this study for the first time in a closed and an open-shell nucleus in the fp-shell. The transfer cross-sections for ground-state to ground-state (J=0+, T=1) and to the first (J=1+, T=0) state were extracted for both cases together with the transfer cross-section ratios σ(0+,T=1)/σ(1+,T=0). They are compared with second-order distorted-wave born approximation (DWBA) calculations. The enhancement of the ground-state to ground-state pair transfer cross-section close to mid-shell, in 52Fe, points towards a superfluid phase in the isovector channel. For the “deuteron-like” transfer, very low cross-sections to the first (J=1+, T=0) state were observed both for 56Ni(p,3He) and 52Fe(p,3He) and are related to a strong hindrance of this channel due to spin-orbit effect. No evidence for an isoscalar deuteron-like condensate is observed.