Model Independent Direct Detection Analyses

TL;DR

This paper conducts a comprehensive analysis of experimental constraints on elastic dark matter scattering within a general effective theory framework, exploring nuclear responses, interference effects, and experiment complementarity.

Contribution

It introduces a model-independent approach to analyze direct detection data, including additional nuclear responses and interference effects, providing a more complete understanding of experimental sensitivities.

Findings

No elastic dark matter explanation of DAMA is consistent with all other experiments at 90% confidence.

Interference effects can create sensitivity holes in parameter space.

Combining experiments improves bounds on dark matter interactions.

Abstract

Following the construction of the general effective theory for dark matter direct detection in 1203.3542, we perform an analysis of the experimental constraints on the full parameter space of elastically scattering dark matter. We review the prescription for calculating event rates in the general effective theory and discuss the sensitivity of various experiments to additional nuclear responses beyond the spin-independent (SI) and spin-dependent (SD) couplings: an angular-momentum-dependent (LD) and spin-and-angular-momentum-dependent (LSD) response, as well as a distinction between transverse and longitudinal spin-dependent responses. We consider the effect of interference between different operators and in particular look at directions in parameter space where such cancellations lead to holes in the sensitivity of individual experiments. We explore the complementarity of different experiments by looking at the improvement of bounds when experiments are combined. Finally, our scan through parameter space shows that within the assumptions on models and on the experiments' sensitivity that we make, no elastically scattering dark matter explanation of DAMA is consistent with all other experiments at 90%, though we find points in parameter space that are ruled out only by about a factor of 2 in the cross-section.