Supersymmetric particles with internal symmetries and central charges

We propose two pseudoclassical particle models invariant under extended Poincare supersymmetry with central charges. In the first model the central charge provides the mass term breaking the U(N) internal symmetry and in the second model the U(N) symmetry is preserved. We show that there is a complete analogy between the appearance of the nonrelativistic mass as a parameter which characterizes the central extensions of the Galilei group and the appearance of the fermion mass through the central extensions of the extended Poincare supergroup. (orig.)