The Nuclear Pseudo-spin Symmetry in Covariant Energy-Density Functional Theory

International audienceThe pseudo—spin symmetry (PSS) in nuclei is the name for the quasi-degeneracy of a pair of single-particle states with quantum numbers (n, Lj) and (n' = n— l, l' = (+2, 3" = j + 1). The PSS is known to exist in many cases, in spherical as well as deformed nuclei. In these lectures, we will discuss this property of atomic nuclei in the framework of a covariant energy-density functional theory (CEDFT) which can describe quantitatively well the properties of spherical as well as deformed nuclei. In particular, we show how perturbation theory can be used to investigate the PSS by relating the nuclear Dirac Hamiltonian of CEDFT to relativistic harmonic oscillator (RHO) potentials