Vectorlike Leptons as the Tip of the Dark Matter Iceberg

A vectorlike lepton could make up a tiny fraction of the dark matter. Its large Z-boson mediated direct detection cross section can compensate for the small relic abundance, giving rise to an interesting signal at future experiments—perhaps even the first one detected. We discuss how such a scenario might arise in the context of a simple non-thermal cosmology and investigate bounds from direct detection experiments and whether this scenario might be probed at the LHC. Searches for disappearing tracks appear promising.