Nuclear structure aspects of spin-independent WIMP scattering off xenon

TL;DR

This paper uses advanced shell-model calculations to analyze the nuclear structure factors relevant for spin-independent WIMP scattering off xenon, showing good agreement with phenomenological models and implications for dark matter detection.

Contribution

It provides detailed shell-model based calculations of structure factors for xenon isotopes, improving understanding of nuclear responses in dark matter searches.

Findings

Structure factors agree with Helm form factors for relevant momentum transfers.

Inelastic scattering is suppressed by ~10^{-4} compared to elastic scattering.

Inelastic scattering can discriminate between spin-independent and spin-dependent interactions.

Abstract

We study the structure factors for spin-independent WIMP scattering off xenon based on state-of-the-art large-scale shell-model calculations, which are shown to yield a good spectroscopic description of all experimentally relevant isotopes. Our results are based on the leading scalar one-body currents only. At this level and for the momentum transfers relevant to direct dark matter detection, the structure factors are in very good agreement with the phenomenological Helm form factors used to give experimental limits for WIMP-nucleon cross sections. In contrast to spin-dependent WIMP scattering, the spin-independent channel, at the one-body level, is less sensitive to nuclear structure details. In addition, we explicitly show that the structure factors for inelastic scattering are suppressed by ~ 10^{-4} compared to the coherent elastic scattering response. This implies that the detection of inelastic scattering will be able to discriminate clearly between spin-independent and spin-dependent scattering. Finally, we provide fits for all calculated structure factors.