  We report the Coulomb mediated hybridization of excitonic states in an
optically active, artificial quantum dot molecule. By probing the optical
response of the artificial molecule as a function of the static electric field
applied along the molecular axis, we observe unexpected avoided level crossings
that do not arise from the dominant single particle tunnel coupling. We
identify a new few-particle coupling mechanism stemming from Coulomb
interactions between different neutral exciton states. Such Coulomb resonances
hybridize the exciton wave function over four different electron and hole
single-particle orbitals. Comparisons of experimental observations with
microscopic 8-band $k \cdot p$ calculations taking into account a realistic
quantum dot geometry show good agreement and reveal that the Coulomb resonances
arise from broken symmetry in the artificial molecule.
