Quantum N = 3, d = 3 Chern-Simons matter theories in harmonic superspace

We develop the background field method for studying classical and quantum aspects of N = 3, d = 3 Chern-Simons and matter theories in N = 3 harmonic superspace. As one of the immediate consequences, we prove a nonrenormalization theorem implying the ultra-violet finiteness of the corresponding supergraph perturbation theory. We also derive the general hypermultiplet and gauge superfield propagators in a Chern-Simons background. The leading supergraphs with two and four external lines are evaluated. In contrast to the non-supersymmetric theory, the leading quantum correction to the massive charged hypermultiplet proves to be the super Yang-Mills action rather than the Chern-Simons one. The hypermultiplet mass is induced by a constant triplet of central charges in the N = 3, d = 3 Poincare superalgebra.