Dark Matter EFT Landscape Probed by QUEST-DMC

TL;DR

This paper evaluates QUEST-DMC's projected ability to detect light dark matter through non-relativistic EFT operators using superfluid helium-3, exploring new interaction models and parameter space in direct detection experiments.

Contribution

It introduces a comprehensive analysis of QUEST-DMC's sensitivity to a complete set of EFT operators, mapping relativistic interactions to non-relativistic operators, and assesses detection potential for sub-GeV dark matter.

Findings

QUEST-DMC can probe previously unexplored parameter space for momentum- and velocity-dependent interactions.

The experiment's sensitivity extends to sub-GeV dark matter masses.

The analysis includes attenuation effects due to Earth's atmosphere and scattering in the Earth.

Abstract

We present the projected sensitivity to non-relativistic Effective Field Theory (EFT) operators for Dark Matter (DM) direct detection using the QUEST-DMC experiment. QUEST-DMC employs superfluid Helium-3 as a target medium and measures energy deposition via nanomechanical resonators with SQUID-based readout to probe DM interactions. The experiment aims to explore new parameter space in the sub-GeV mass range, probing light DM and a broad range of interaction models. We analyse the sensitivity to a complete set of fourteen independent non-relativistic EFT operators, each parameterised by a Wilson coefficient that quantifies the strength of DM interactions with Standard Model particles. For each interaction channel, we determine the corresponding sensitivity ceiling due to attenuation of the DM flux incident on the detector, caused by DM scattering in the Earth and atmosphere. As a key component of this analysis, we provide the mapping between the non-relativistic EFT operators and the relativistic bilinear DM-nucleon interactions, and assess the interaction sensitivity to sub-GeV DM in the QUEST-DMC detector. Our findings demonstrate that QUEST-DMC provides a unique probe of DM interactions, particularly in previously unexplored parameter space for momentum- and velocity-dependent interactions, thereby expanding the search for viable DM candidates beyond traditional weakly interacting massive particles.