Abstract
We study the ground and excited resonance states of with a three-body model of taking into account the coupling to the continuum. To this end, we use the new experimental data for the invariant mass spectroscopy of the unbound and nuclei, and present an update of three-body model calculations for the two-neutron decay of the nucleus. With the new model inputs determined with the ground-state decay of , we discuss the dineutron correlations and a halo nature of this nucleus, as well as the structure of the excited states. For the energy of the state, we achieve an excellent agreement with the experimental data with this calculation. We show that the state consists predominantly of the configuration, for which the pairing interaction between the valence neutrons slightly decreases its energy from the unperturbed one. We also discuss the structure of excited states of the nucleus. In particular, we show the existence of an excited state at 3.38 MeV, which is mainly composed of the configuration.
6 More- Received 5 February 2016
DOI:https://doi.org/10.1103/PhysRevC.93.034330
©2016 American Physical Society