Light Dark Matter through Assisted Annihilation

摘要: In this paper we investigate light dark matter scenarios where annihilation to Standard Model particles at tree-level is kinematically forbidden. such cases can be aided by massive Model-like species, called {\it assisters}, in the initial state that enhances available phase space opening up novel processes. We feasibility of non-standard assisted annihilation} processes reproduce observed relic density matter. present a simple scalar - assister model realised. find if and are relatively degenerate required achieved for keV-MeV scale briefly discuss cosmological constraints on scenarios.