Supernova constraints on MeV dark sectors from e+e- annihilations

Theories with dark forces and dark sectors are of interest for dark matter models. In this paper we find the region in parameter space that is constrained by supernova cooling constraints when the models include dark sector particles with masses around 100 MeV or less. We include only interactions with electrons and positrons. The constraint is important for small mixing parameters. We do not include in this work interactions with nucleons, which could give other important constraints.