Analysis strategies for general spin-independent WIMP-nucleus scattering

TL;DR

This paper develops a comprehensive formalism for analyzing spin-independent WIMP-nucleus scattering in dark matter detection, incorporating chiral effective field theory and nuclear structure calculations to improve interpretation of experimental results.

Contribution

It introduces a unified framework that includes all relevant interactions and corrections, extending standard analyses with new physics couplings and two-body current effects.

Findings

Identifies interference effects with isovector responses as significant corrections.

Provides structure factor fits for xenon targets using advanced nuclear shell-model calculations.

Highlights the importance of two-body currents and interference terms in interpreting detection data.

Abstract

We propose a formalism for the analysis of direct-detection dark-matter searches that covers all coherent responses for scalar and vector interactions and incorporates QCD constraints imposed by chiral symmetry, including all one- and two-body WIMP-nucleon interactions up to third order in chiral effective field theory. One of the free parameters in the WIMP-nucleus cross section corresponds to standard spin-independent searches, but in general different combinations of new-physics couplings are probed. We identify the interference with the isovector counterpart of the standard spin-independent response and two-body currents as the dominant corrections to the leading spin-independent structure factor, and discuss the general consequences for the interpretation of direct-detection experiments, including minimal extensions of the standard spin-independent analysis. Fits for all structure factors required for the scattering off xenon targets are provided based on state-of-the-art nuclear shell-model calculations.