Relativistic description of drip line nuclei

Nuclei in the vicinity of the neutron drip line are investigated in the mean field approximation. Pairing correlations have to be taken into account in this region. If the Fermi surface is near the continuum limit, pairs of nucleons can be scattered to thee continuum. Relativistic Hartree-Bogoliubov theory based on an effective density dependence pairing interaction of zero range is used to describe this correlation. It is found that the neutron halo in the nucleus 11 Li can be reproduced in this way without any additional parameter. It is formed by the scattering of Cooper pairs into the continuum. Several other cases of nuclear halos are predicted. In particular also multi-nucleon halos. (author)