  Recent results from the PAMELA experiment indicate an excess in the positron
spectrum above 10 GeV, but anti-proton data are consistent with the expected
astrophysical backgrounds. We propose a scenario that reproduces these
features. Dark matter annihilates through channels involving a new heavy
vectorlike lepton which then decays by mixing with Standard Model leptons. If
charged, this heavy lepton might be produced at the LHC, and could lead to
multi-lepton final states or to long-lived charged tracks. Large neutrino
detectors such as ANTARES or IceCube might be sensitive to a monochromatic
neutrino line. This scenario may be simply embedded in various models,
including an extension to the NMSSM.
