Giant Neutron Halo in Exotic Calcium Nuclei

The properties of even-even Ca isotopes are studied using the relativistic continuum Hartree-Bogoliubov theory.The calculations Reproduce very well the experimental binding energies E and two neutron separation energies S2n.The predicted neutron drip nuclei is &72Ca.From the analysis of S2n,the neutron radii and neutron density distribution,giant neutron haloes are predicted in Ca isotopes with A>60.