Influence of pairing correlations on the size of the nucleus in relativistic continuum Hartree-Bogoliubov theory

The influence of pairing correlations on the size of the nucleus and the development of nuclear halos is studied in the framework of relativistic continuum Hartree-Bogoliubov theory. It turns out that the contributions of weakly bounded orbits in the continuum with low orbital angular momenta l play an essential role. Pairing correlations have a two-fold influence on the density distribution of the neutrons and therefore on the total nuclear size. First, they can change the root-mean-square radius of the individual weakly bound orbits and, second, they can change the occupation probabilities of these orbits in the nuclear system. Both effects are important, and finally the total radius is dominated by their competition.