Analysis of the Unbound Spectra of 12Li and 13Li

Abstract: The properties of unbound nuclei 12Li and 13Li are calculated within themultistep shell model in the complex energy plane by assuming that the spectraare determined by the motion of neutrons outside the 9Li core. It is foundthat in 12Li the ground state consists of an antibound 1/2+ state and thatonly this and a 1/2? and a 5/2+ excited states are physically meaningfulresonances. Calculations suggest that there is no bound or antibound statein 13Li.