[en] The supersymmetric massless states of a relativistic extension of Witten's supersymmetric quantum mechanics are shown to correspond to abelian gauge fields realized by antisymmetric tensors. The massive states, which are only partially supersymmetric, include spin-1 and spin-0 particles. In particular the Maxwell and Proca fields are obtained from N = 2 supersymmetric relativistic mechanics by first quantization in much the same way as the Dirac theory arises in the N = 1 case. The particles may be coupled supersymmetrically to external scalar and complex hermitian tensor fields. The latter reduce in special cases to the Riemannian metric of external gravitation and the Kaehler metric implied by a vector field coupling. All the couplings exhibit a quadrupole characteristics of the particles. In particular supersymmetry requires their electric charge and magnetic dipole moment to vanish, and there is no coupling to torsion in Riemann-Cartan spacetime. Quantization in external fields yields covariant generalizations of the classical tensor field equations. Finally classical equations of translational and spin motion involving only real quantities are obtained from the Heisenberg equations. (Author)