Halo neutrons and the {beta} decay of {sup 11}Li

The {beta} decay of {sup 11}Li has been investigated at TRIUMF-ISAC using a high-efficiency array of Compton suppressed HPGe detectors. From a line-shape analysis of the Doppler-broadened peaks observed in the {sup 10}Be {gamma} spectrum, both the half-lives of states in {sup 10}Be and the energies of the {beta}-delayed neutrons feeding those states were obtained. Furthermore, it was possible to determine the excitation energies of the parent states in {sup 11}Be with uncertainties comparable to those obtained from neutron spectroscopy experiments. These data suggest that the {beta} decay to the 8.81 MeV state in {sup 11}Be occurs in the {sup 9}Li core and that one neutron comprising the halo of {sup 11}Li survives in a halolike configuration after the {beta}-delayed neutron emission from this level.