A new effective Lagrangian for nuclear matter

The Zimányi-Moszkowski (ZM) Lagrangian describes nuclear matter and stable finite nuclei in the relativistic mean field approximation and even in the non-relativistic limit. It fails, however, to predict the correct non-relativistic spin-orbit (SO) coupling. In this paper we improve on this matter by an additional tensor coupling analogous to the one which leads to the anomalous gyromagnetic ratio. It can be adjusted to describe the SO-term without changing the mean field solution of the ZM-Lagrangian for nuclear matter.