Non-linear derivative interactions in relativistic hadrodynamics

The Lagrangian density of Relativistic Hadrodynamics (RHD) is extended by introducing non-linear derivative (NLD) interactions of the nucleon with the meson fields. As a consequence, the nucleon selfenergy becomes both momentum and density dependent. With a single cut-off parameter, which regulates the NLD Lagrangian, our approach is compatible with results from microscopic nuclear matter calculations as well as with Dirac phenomenology. It also reproduces the correct behavior of the real part of the proton-nucleus potential both at low and at high proton energies.