title: Derivation of Dark Matter Parity from Lepton Parity.
abstract: It is shown that in extensions of the standard model of quarks and leptons where the additive lepton number L is broken by two units, so that Z_{2} lepton parity, i.e., (-1)L which is either even or odd, remains exactly conserved, there is the possibility of stable dark matter without additional symmetry. This applies to many existing simple models of Majorana neutrino mass with dark matter, including some radiative models. Several well-known examples are discussed. This new insight leads to the construction of a radiative type II seesaw model of neutrino mass with dark matter where the dominant decay of the doubly charged Higgs boson ξ++ is into W+W+ instead of the expected li+lj+ lepton pairs for the well-known tree-level model.
authors.affiliation: Physics and Astronomy Department and Graduate Division, University of California, Riverside, California 92521, USA and HKUST Jockey Club Institute for Advanced Study, Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Ernest
authors.initials: E
authors.lastname: Ma