  We study a class of simplified dark matter models in which dark matter
couples directly with a mediator and a charged lepton. This class of Lepton
Portal dark matter models has very rich phenomenology: it has loop generated
dark matter electromagnetic moments that generate a direct detection signal; it
contributes to indirect detection in the cosmic positron flux via dark matter
annihilation; it provides a signature of the same-flavor, opposite-sign
dilepton plus missing transverse energy at colliders. We determine the current
experimental constraints on the model parameter space for Dirac fermion,
Majorana fermion and complex scalar dark matter cases of the Lepton Portal
framework. We also perform a collider study for the 14 TeV LHC reach with 100
inverse femtobarns for dark matter parameter space. For the complex scalar dark
matter case, the LHC provides a very stringent constraint and its reach can be
interpreted as corresponding to a limit as strong as two tenths of a zeptobarn
on the dark matter-nucleon scattering cross section for dark matter masses up
to 500 GeV. We also demonstrate that one can improve the current collider
searches by using a Breit-Wigner like formula to fit the dilepton MT2 tail of
the dominant diboson background.
