There is overwhelming evidence for the existence of an unknown mass in the universe, namely dark matter (DM). Major experimental efforts attempting to search for these DM interactions are currently in place, with no evidence of discovery so far.
A class of DM candidates, sub-GeV DM, has been gaining significant interest in recent years since it can account for the abundance of DM in the universe while evading current experimental constraints. Since such light DM cannot be probed so easily via nuclear or even electron recoils, accelerator experiments, which aim to produce relativistic DM, are ideal for this mass range.
In the first part of this talk, we consider both simplified DM models in which the Standard Model is extended by one spin-1 DM candidate along with one spin-1 mediator, and an ultraviolet complete model based on a non-abelian gauge group where DM is a spin-1 Strongly Interacting Massive Particle (SIMP). We find that spin-1 DM is testable by future experiments, and for certain spin-1 models, will be the first DM models probed by the upcoming (Light Dark Matter eXperiment) LDMX.
In the second part, we discuss combining relevant experimental constraints for sub-GeV DM in a statistically robust way. By performing global fits using the new sub-GeV branch of the software GAMBIT, we can calculate a combined likelihood for various DM models, which includes new additions to the software such as fixed target experiment likelihoods.