Froggatt-Nielsen model for leptophilic scalar dark matter decay
Abstract
We construct a model of decaying, TeV-scale scalar dark matter motivated by data from the PAMELA and Fermi-LAT experiments. By introducing an appropriate Abelian discrete symmetry and an intermediate scale of vectorlike states that are responsible for generating lepton Yukawa couplings, we show that Planck-suppressed corrections may lead to decaying dark matter that is leptophilic and has the desired lifetime. The dark matter candidate decays primarily to lepton/antilepton pairs, and at a subleading rate to final states with a lepton, antilepton and standard model Higgs boson. We show that the model can reproduce the observed positron flux and positron fraction while remaining consistent with the bounds on the cosmic ray antiproton flux.