Searching for Dark Matter at Accelerator-Based Experiments

The evidence for dark matter is strong. However, the constituents of dark matter are still unknown, and the viable possibilities span a large mass range. The thermal relic dark matter hypothesis sharpens the focus on a narrower range of masses. Considerable experimental attention has been given to exploring Weakly Interacting Massive Particles in the upper end of this range (few GeV – ~TeV), while the region ~MeV to ~GeV is largely unexplored. A thermal origin for dark matter works in a simple and predictive manner in this mass range, and it requires a production mechanism in accelerator-based experiments. I'll discuss several ways that beam-dump experiments can probe this mass range with exciting new sensitivity.