Covariant theory of particle-vibrational coupling and its effect on the single-particle spectrum

The relativistic mean field (RMF) approach describing the motion of independent particles in effective meson fields is extended by a microscopic theory of particle vibrational coupling. It leads to an energy dependence of the relativistic mass operator in the Dyson equation for the single-particle propagator. This equation is solved in the shell-model of Dirac states. As a result of the dynamics of particle-vibrational coupling we observe a noticeable increase of the level density near the Fermi surface. The shifts of the single-particle levels in the odd nuclei surrounding {sup 208}Pb and the corresponding distributions of the single-particle strength are discussed and compared with experimental data.