# New Constraints on Xenonphobic Dark Matter from DEAP-3600

## TL;DR

The DEAP-3600 experiment provides new constraints on xenonphobic dark matter, especially in isospin-violating scenarios where it surpasses other experiments in limiting dark matter-proton interactions.

## Contribution

This study demonstrates that DEAP-3600 sets the most stringent limits on certain isospin-violating dark matter models, highlighting the importance of diverse detection targets.

## Key findings

- DEAP-3600 constrains xenonphobic dark matter more effectively than previous experiments.
- Isospin violation allows DEAP-3600 to outperform xenon-based detectors in specific parameter regions.
- Results emphasize the importance of multiple detection methods for understanding dark matter properties.

## Abstract

The first-year results from DEAP-3600, a single-phase liquid argon direct-detection dark matter experiment, were recently reported. At first sight, they seem to provide no new constraints, as the limit lies well within the region already excluded by three different xenon experiments: LUX, PandaX-II, and XENON1T. We point out, however, that this conclusion is not necessarily true, for it is based on the untested assumption that the dark matter particle couples equally to protons and neutrons. For the more general case of isosping-violating dark matter, we find that there are regions in the parameter space where DEAP-3600 actually provides the most stringent limits on the dark matter-proton spin-independent cross section. Such regions correspond to the so-called Xenonphobic dark matter scenario, for which the neutron-to-proton coupling ratio is close to $-0.7$. Our results seem to signal the beginning of a new era in which the complementarity among different direct detection targets will play a crucial role in the determination of the fundamental properties of the dark matter particle.