Probing the $^{8}$He ground state via the $^{8}$He(p,t)$^{6}$He reaction

• Published in: Physics letters. B Vol. 646; pp. 222 - 226
• Main Authors: Keeley, N., Skaza, F., Lapoux, V., Alamanos, N., Auger, F., Beaumel, D., Becheva, E., Blumenfeld, Y., Delaunay, F., Drouart, A., Gillibert, A., Giot, Lydie, Kemper, K.W., Nalpas, L., Pakou, A., Pollacco, E.C., Raabe, R., Roussel-Chomaz, P., Rusek, K., Scarpaci, J.-A., Sida, J.-L., Stepantsov, S., Wolski, R.
• Format: Journal Article
• Language: English
• Published: Elsevier 22.03.2007
• Subjects: Nuclear Experiment; Physics; Spectroscopy; CRC calculations; 8He; Direct reactions
• ISSN: 0370-2693
• DOI: 10.1016/j.physletb.2007.01.035

The weakly-bound 8He nucleus exhibits a neutron halo or thick neutron skin and is generally considered to have an α+4n structure in its ground state, with the four valence neutrons each occupying 1p3/2 states outside the α 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 Click to view the MathML source, 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.