The weakly interacting massive particle paradigm for dark matter is currently being probed via many different experiments. Direct detection, indirect detection and collider searches are all hoping to catch a glimpse of these elusive particles. Here, we examine the potential of the International Linear Collider (ILC) to shed light on the origin of dark matter. By using an effective field theory approach we are also able to compare the reach of the ILC with that of the other searches. We find that for low mass dark matter ($<10\mathrm{GeV}$), the ILC offers a unique opportunity to search for interacting massive particles beyond any other experiment. In addition, if dark matter happens to only couple to leptons or via a spin dependent interaction, the ILC can give an unrivalled window to these models. We improve on previous ILC studies by constructing a comprehensive list of effective theories that allows us to move beyond the nonrelativistic approximation.

• Received 14 December 2012

DOI:https://doi.org/10.1103/PhysRevD.87.075015