Halo-independent tests of dark matter direct detection signals: local DM density, LHC, and thermal freeze-out

TL;DR

This paper develops halo-independent methods to analyze dark matter direct detection signals, enabling comparisons with astrophysical data, collider limits, and thermal relic conditions without assumptions on the local dark matter velocity distribution.

Contribution

It introduces a model-independent bound linking direct detection signals with local dark matter density, collider constraints, and thermal relic conditions.

Findings

Derived a lower bound on the DM-nucleon cross section times local DM density.

Showed how to compare direct detection signals with LHC limits independently of velocity distribution.

Applied the method to a simplified Z' mediator model with future xenon experiment data.

Abstract

From an assumed signal in a Dark Matter (DM) direct detection experiment a lower bound on the product of the DM--nucleon scattering cross section and the local DM density is derived, which is independent of the local DM velocity distribution. This can be combined with astrophysical determinations of the local DM density. Within a given particle physics model the bound also allows a robust comparison of a direct detection signal with limits from the LHC. Furthermore, the bound can be used to formulate a condition which has to be fulfilled if the particle responsible for the direct detection signal is a thermal relic, regardless of whether it constitutes all DM or only part of it. We illustrate the arguments by adopting a simplified DM model with a Z' mediator and assuming a signal in a future xenon direct detection experiment.