Discovering asymmetric dark matter with anti-neutrinos

Abstract

We discuss possible signatures of Asymmetric Dark Matter (ADM)through dark matter decays to neutrinos.We specifically focus on scenarios in whichthe Standard Model (SM) baryon asymmetry is transferred to the dark sector(DS) through higher dimensional operators in chemical equilibrium.In such cases, the dark matter (DM) carries lepton and/or baryon number, andwe point out that for a wide range of quantum number assignments,by far the strongest constraints on dark matter decays come fromdecays to neutrinos through the ``neutrino portal'' operatorHL. Together with the facts that ADM favorslighter DM masses ∼ a few GeV and that the decays would lead only toanti-neutrinos and no neutrinos (or vice versa), the detectionof such decays at neutrino telescopes would provide compellingevidence for ADM. We discuss current and future bounds onmodels where the DM decays to neutrinos through operatorsof dimension ⩽ 6. For dimension 6 operators, the scale suppressingthe decay is bounded to be ≳1012–1013 GeV.