| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1838589 | Nuclear Physics A | 2010 | 18 Pages |
The unbound nuclei 9He and 10He have been produced in proton-knockout reactions from a 280 MeV/u 11Li beam impinging on a liquid hydrogen target at the ALADIN-LAND setup at GSI. Information on their nuclear structure has been obtained from the relative-energy spectra, and , employing reaction models incorporating the structure of 11Li.The relative-energy spectrum is dominated by a strong peak-like structure at low energy, which may be interpreted within the effective-range approximation as the result of an s-wave interaction with a neutron scattering length of −3.17(66) fm. This spectrum also shows evidence for resonance states at 1.33(8) MeV and at 2.4 MeV above the threshold. It is argued that the s-state might not be the 9He ground state.For , the analysis of the relative-energy spectrum gives two alternative possibilities for an interpretation: either a narrow resonance at 1.42(10) MeV (Γ=1.11(76)MeV) superimposed on a correlated background, or two overlapping resonances, a ground state at 1.54(11) MeV (Γ=1.91(41)MeV) together with an excited state at 3.99(26) MeV (Γ=1.64(89)MeV). The two possible interpretations are discussed.
