Characterisation of Dark Matter in Direct Detection Experiments: Singlino Versus Higgsino

TL;DR

This paper presents a method to distinguish between Singlino and Higgsino dark matter candidates in direct detection experiments, using a model-independent analysis applicable to various BSM scenarios and detector types.

Contribution

It introduces a general $$ analysis framework for identifying dark matter nature in direct detection data, applicable beyond specific models.

Findings

Effective discrimination between Singlino and Higgsino candidates demonstrated.

Method applicable to Xenon, Germanium, and Silicon detectors with complementary sensitivities.

Model-independent approach aids broader BSM dark matter studies.

Abstract

We show how the material used in direct detection experiments of Dark Matter (DM), in the presence of a signal of it, can afford one with the possibility of extracting the nature of the underlying candidate. We do so for the case of a $U(1)'$ Supersymmetric Standard Model (USSM) of E$_6$ origin, by exploiting benchmark points over its parameter space that yield either a Singlino- or Higgsino-like neutralino as DM candidate, the latter being defined in presence of up-to-date constraints, from low to high energy and from collider to non-collider experiments. However, as our method is general, we also introduce a model-independent description of our analysis, for the purpose of aiding similar studies in other Beyond the Standard Model (BSM) scenarios. This has been made possible by adapting a rather simple $\chi^2$ analysis normally used for signal extraction in direct detection experiments and the procedure has been applied to Xenon, Germanium and Silicon detectors, those showing maximal and complementary sensitivity to gauge- and Higgs-portal induced interactions of DM with their nuclei.