Study of ground state properties of carbon isotopes with deformed relativistic Hartree-Bogoliubov theory in continuum

Ground state properties of carbon isotopes, including root-mean-square radii, neutron separation energies, single particle spectra, and shapes are systematically studied with the deformed relativistic Hartree-Bogoliubov theory in continuum. The calculations with the effective interaction PK1 reproduce the available data reasonably well. The shell evolution in this isotopic chain is investigated by examining the single particle spectra. The inversion of neutron orbitals $ν2s_{1/2}$ and $ν1d_{5/2}$ compared with the order of neutron orbitals in stable nuclei is revealed in $^{15-20,22}\mathrm{C}$ when these nuclei are constrained to spherical shape. Neutron halos in $^{15,19,22}$C are studied in detail and their halo structures are mainly caused by the inversion of ($ν2s_{1/2},ν1d_{5/2}$) and deformation effects. In particular, $^{15}$C and $^{22}$C are deformed halo nuclei with shape decoupling effects in ground states.