  In this paper we propose and analyze a new coupling procedure for the
Hybridizable Discontinuous Galerkin Method with Galerkin Boundary Element
Methods based on a double layer potential representation of the exterior
component of the solution of a transmission problem. We show a discrete uniform
coercivity estimate for the non-symmetric bilinear form and prove optimal
convergence estimates for all the variables, as well as superconvergence for
some of the discrete fields. Some numerical experiments support the theoretical
findings.
