Pairing correlations and resonant states in the relativistic mean field theory

We present a simple scheme for taking into account the resonant continuum coupling in the relativistic mean field-BCS calculations. In this scheme, applied before in nonrelativistic calculations, the effect of the resonant continuum on pairing correlations is introduced through the scattering wave functions located in the region of the resonant states. These states are found by solving the relativistic mean field equations with scattering-type boundary conditions for the continuum spectrum. The calculations are done for the neutron-rich Zr isotopes. It is shown that the sudden increase of the neutron radii close to the neutron drip line, the so-called giant halo, is determined by a few resonant states close to the continuum threshold.