Nuclear structure studies of bound and unbound states in drip-line nuclei

The structure of the neutron-rich isotopes7He,10Li and11Be has been studied in detail using multi-nucleon transfer reactions. New results have been obtained for7He, where we have evidence for the observation of the first excited state, i.e. the 1/2--resonance, which is of interest for the spin-orbit splitting in these light neutron-rich nuclei. Reactions of distinct selectivity have been chosen to study the states of10Li, which are all unbound. The structure of the eight states found in these reactions is discussed, and the relevance for the decay of11Li resonances is shown. The isotopes10Be and11Be have been investigated to study the α-cluster structure and high-lying states. Nine states of the observed11Be-resonances form a molecu-lar rotational band. The multi-nucleon transfer mechanism has also been applied to study the unbound proton-rich isotope11N, the mirror nucleus of11Be. In this case the12C(14N,15C)11N-reaction has been used. Five resonances have been observed, and the lowest two can be identified as 1/2- -and 5/2+ -states.