Speaker
Description
The QUEST-DMC experiment utilises surface-based superfluid helium-3 bolometers to search for sub-GeV dark matter with ultra-low energy thresholds. This talk presents a study of how different dark matter interaction types impact QUEST-DMC's projected sensitivity. As a central component, we map the non-relativistic EFT operators onto the relativistic bilinear DM-nucleon interactions basis relevant at detector scales, and quantify QUEST-DMC sensitivity across interaction types. We show that QUEST-DMC provides a unique probe of dark matter interactions, with particular strength in previously unexplored parameter space for momentum- and velocity-dependent couplings, extending direct-detection coverage beyond traditional WIMP scenarios.
To connect this reach to collider constraints and cosmological targets in a consistent framework, we use a generalised BSM parton shower through Monte-Carlo event generation and developed two new UFO implementations corresponding to the canonical spin-independent and spin-dependent interactions. This enables sub-GeV dark matter event generation at hadron collider level, allowing collider cross-section limits to be derived in the sub-GeV mass range and compared directly to the corresponding thermal freeze-out targets. We confront these collider-based constraints with the QUEST-DMC reach, highlighting where QUEST-DMC offers uniquely strong coverage of currently unconstrained parameter space and where collider and cosmological considerations are complementary.