Kinetic Mixing as the Origin of Light Dark Scales

TL;DR

This paper introduces a simple supersymmetric dark matter model with a kinetically mixed U(1)_d gauge symmetry, explaining cosmic ray excesses and linking observable signals to fundamental parameters.

Contribution

It presents a minimal model connecting dark matter, kinetic mixing, and observable cosmic ray signals, with parameter constraints derived from observational data.

Findings

Relates DAMA cross section to hypercharge D-term VEV

Fixes dark matter mass using cosmic ray data

Predicts signals for future detection experiments

Abstract

We propose a model in which supersymmetric weak scale dark matter is charged under a U(1)_d dark gauge symmetry. Kinetic mixing between U(1)_d and hypercharge generates the appropriate hierarchy of scales needed to explain PAMELA and ATIC with a GeV scale force carrier and DAMA (or INTEGRAL) using the proposals of inelastic (or, respectively, exciting) dark matter. Because of the extreme simplicity of this setup, observational constraints lead to unambiguous determination of the model parameters. In particular, the DAMA scattering cross section is directly related to the size of the hypercharge D-term vacuum expectation value. The known relic abundance of DM can be used to fix the ratio of the dark sector coupling to the dark matter mass. Finally, the recent observation of cosmic ray positron and electron excesses can be used to fix the mass of the dark matter through the observation of a shoulder in the spectrum and the size of the kinetic mixing by fitting to the rate. These parameters can be used to make further predictions, which can be checked at future direct detection, indirect detection, as well as collider experiments.