| N. Keeley, F. Skaza, V. Lapoux, N. Alamanos, F. Auger, D. Beaumel, E. Becheva, Y. Blumenfeld, F. Delaunay, A. Drouart, A. Gillibert, L. Giot, K.W. Kemper, L. Nalpas, A. Pakou, E.C. Pollacco, R. Raabe, P. Roussel-Chomaz, K. Rusek, J.-A. Scarpaci, J.-L. Sida, S. Stepantsov, and R. Wolski. |
The weakly-bound 8He nucleus exhibits a neutron halo or skin and is generally considered to have an alpha+4n structure
in its ground state, with the four valence neutrons each occupying 1p3/2 states outside the alpha core. The 8He(p,t)6He
reaction is a sensitive probe of the ground state structure of 8He, and we present a consistent analysis of new and existing
data for this reaction at incident energies of 15.7 and 61.3 A MeV, respectively. Our results are incompatible with the usual
assumption of a pure (1p3/2)^4 structure and suggest that other configurations such as (1p3/2)^2(1p1/2)^2 may be present
with significant probability in the ground state wave function of 8He. |
