| F. Skaza, V. Lapoux, N. Keeley, N. Alamanos, F. Auger, D. Beaumel, E. Becheva, Y. Blumenfeld, F. Delaunay, A. Drouart, A. Gillibert, L. Giot, E. Khan, L. Nalpas, A. Pakou, E. Pollacco, R. Raabe, P. Roussel-Chomaz, K. Rusek, J-A. Scarpaci, J-L. Sida, S. Stepantsov and R. Wolski. |
The structure of the light exotic nucleus 8He was investigated using direct reactions of the 8He SPIRAL beam on
a proton-rich target. The (p,p\') scattering to the 2+ state, the (p,d)7He and (p,t)6He transfer reactions, were
measured at the energy Elab=15.7 A.MeV. The light charged particles (p,d,t) were detected in the MUST Si-strip
telescope array. The excitation spectrum of 8He was extracted from the (p,p\') reaction.
Above the known 2+ excited state at 3.6 MeV, a second resonance was found around 5.4 MeV.
The cross sections were analyzed within the coupled-reaction channels framework, using microscopic potentials.
It is inferred that the 8He ground state has a more complex neutron-skin structure than suggested by previous
alpha+4n models assuming a pure (1p3/2)4 configuration.
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