Neutron halos in deformed nuclei from a relativistic Hartree-Bogoliubov theory in continuum

Full text: In this talk I will present some recent results about neutron halos in deformed nuclei. The halo phenomenon is one of the most interesting topics in modern nuclear physics. Much effort has been focused on the investigation of the structure and dynamics of nuclear halo. Since most open shell nuclei are deformed, the interplay between deformation and weak binding raises interesting questions. In order to give an adequate description of possible halo in a deformed nucleus, a model should be used which includes in a self-consistent way the continuum, deformation effects, large spatial distributions, and couplings among all these features. A deformed relativistic Hartree-Bogoliubov theory in continuum has been developed for this purpose and the halo phenomenon in deformed weakly bound nuclei is investigated. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nuclei 42;44Mg. The cores of these two nuclei are prolate, but the halos have slightly oblate shapes. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the existence of halos in deformed nuclei and for the occurrence of this decoupling effect are discussed. (author)