Hidden Sector Dirac Dark Matter, Stueckelberg Z' Model and the CDMS and XENON Experiments

TL;DR

This paper analyzes milli-charged Dirac dark matter within the Stueckelberg Z' model, evaluating its detection prospects and compatibility with experimental limits from CDMS II and XENON100, and discusses the model's general applicability.

Contribution

It introduces a detailed calculation of dark matter interactions in the Stueckelberg Z' model and assesses their consistency with current direct detection experimental constraints.

Findings

Effective couplings are consistent with experimental limits.

Milli-charged dark matter loses energy in the atmosphere before detection.

Results are applicable to other Z-Z' portal models.

Abstract

For the milli-charged Dirac dark matter in the Stueckelberg Z' model, we discuss the contributions from the vector couplings of the dark matter with the neutral gauge bosons to the spin-independent scattering cross section in the direct detections. We also compute the effective coupling between the fermionic dark matter particle and the standard model Higgs boson generated through a triangular loop of Z and/or Z' bosons which may contribute to the spin-independent scattering cross section at the quantum level. We show that the latter contribution is consistent with the most recent experimental limits from CDMS II and XENON100. In the case that the dark matter particle carries a milli-charge of order O(10^{-3}e), we found that it would lose all its kinetic energy by colliding with nucleons in the atmosphere before reaching the detector. Even though we use the Stueckelberg Z' model for illustration, the results we obtain are rather general and applicable to other Z-Z' portal-type hidden-sector models as well.