Hints of giant halo in Zr isotopes by resonant RMF+ACCC+BCS approach

A simple scheme with the single-particle resonant continuum coupling and pairing correlations, is applied to describe the formation of the giant halo for neutron-rich even-even Zr isotopes by the resonant BCS model within the relativistic mean field framework. Resonance parameters and wave functions are extracted from the effective analytic continuation in the coupling-constant approach. It can be seen that the sudden increase of the neutron radii close to the neutron drip line is due to a few resonant states in the vicinity of the Fermi surface.