Neutralino Dark Matter with Light Staus
  In spite of rapid experimental progress, windows for light superparticles
remain. One possibility is a ~100 GeV tau slepton whose t-channel exchange can
give the correct thermal relic abundance for a relatively light neutralino. We
pedagogically review how this region arises and identify two distinct scenarios
that will be tested soon on multiple fronts. In the first, the neutralino has a
significant down-type higgsino fraction and relatively large rates at direct
detection experiments are expected. In the second, there is large mixing
between two relatively light staus, which could lead to a significant excess in
the Higgs boson branching ratio to photons. In addition, electroweak
superpartners are sufficiently light that direct searches should be effective.
