Lawrence Berkeley National Laboratory

While the phenomenon of one- and two-neutron ground-state halo nuclei is well established, the effects of weak binding on nuclear excitation properties remain largely unexplored. Motivated by this question and by recent data in 40Mg we investigate the coupling of weakly bound (halo) valence neutrons to a core using the known properties of 40Mg to explore and illustrate possible particle-core coupling schemes and their impact on the low-lying excitation spectrum.