Complementarity of dark matter direct detection: the role of bolometric targets

TL;DR

This paper explores how combining different bolometric detector materials enhances the ability to determine dark matter particle properties, such as mass and interaction cross sections, by breaking degeneracies present in single experiments.

Contribution

It investigates the use of various scintillating bolometers, like Al2O3, LiF, and CaWO4, to improve the reconstruction of WIMP dark matter parameters beyond traditional germanium and xenon detectors.

Findings

Al2O3 and LiF bolometers enable detection of small SD and SI cross sections.

CaWO4 bolometers can help determine WIMP mass and SI cross section.

Complementary targets improve parameter determination over single experiments.

Abstract

We study how the combined observation of dark matter in various direct detection experiments can be used to determine the phenomenological properties of WIMP dark matter: mass, spin-dependent (SD) and spin-independent (SI) scattering cross section off nucleons. A convenient choice of target materials, including nuclei that couple to dark matter particles through a significantly different ratio of SD vs SI interactions, could break the degeneracies in the determination of those parameters that a single experiment cannot discriminate. In this work we investigate different targets that can be used as scintillating bolometers and could provide complementary information to germanium and xenon detectors. We observe that Al2O3 and LiF bolometers could allow a good reconstruction of the DM properties over regions of the parameter space with a SD scattering cross section as small as 10^(-5) pb and a SI cross section as small as 5x10^(-10) pb for a 50 GeV WIMP. In the case of a CaWO4 bolometer the area in which full complementarity is obtained is smaller but we show that it can be used to determine the WIMP mass and its SI cross section. For each target we study the required exposure and background.