Description of Continuum States within the No-Core Shell Model: Single-State HORSE Method

The Single-State HORSE (SS-HORSE) method is applied to studying resonant scattering. The method relies on microscopic calculations of nuclear spectra on the basis of the No-Core Shell Model with realistic nucleon-nucleon interactions and does not involve model approximations. The 3/2− and 1/2− resonances of the 5Li and 5He nuclei are investigated within the SS-HORSE method. The possible existence of a resonance in the four-neutron system is explored.