Relativistic Hartree-Bogoliubov and QRPA description of exotic nuclear structure

The relativistic Hartree-Bogoliubov (RHB) model is extended to include density-dependent meson-nucleon vertex functions. Compared with standard relativistic mean-field effective interactions with non-linear meson-exchange terms, the density-dependent meson-nucleon couplings provide an improved description of asymmetric nuclear matter, neutron matter and nuclei far from stability. The relativistic quasiparticle random-phase approximation (RQRPA) is formulated in the canonical single-nucleon basis of the relativistic Hartree-Bogoliubov (RHB) model. Both in the particle-hole and particle-particle channels, the same interactions are used in the RHB calculation of the ground state and in the matrix equations of the RQRPA. The RHB+RQRPA is employed in the analysis of multipole excitations of neutron-rich oxygen isotopes.