Abstrakt
In this short note we discuss N-supersymmetric worldlines of rela-tivistic massless particles and review the known result that physical spin -N/2 fields are in the first BRST cohomology group. For N = 1, 2, 4, emphasis is given to particular deformations of the BRST differential, that implement either a covariant derivative for a gauge theory or a metric connection in the target space seen by the particle.
In the end, we comment about the possibility of incorporating Ramond-Ramond fluxes in the background.