On the Origin of Light Dark Matter Species

TL;DR

This paper proposes that light, GeV-scale dark matter particles charged under a new gauge force can explain direct detection signals and cosmic-ray anomalies, with specific models and testable predictions.

Contribution

It introduces a model where GeV-Matter explains direct detection signals and cosmic-ray anomalies, and suggests experimental tests in collider datasets.

Findings

GeV-Matter can account for CoGeNT and DAMA signals

Dark higgsinos are natural GeV-Matter candidates

Predicted event rates match observed experimental data

Abstract

TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states -- "GeV-Matter" -- that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark sector are natural candidates for GeV-Matter that scatter off protons with a universal cross-section of 5 x 10^{-38} cm^2 and can naturally be split by 10-30 keV so that their dominant interaction with protons is down-scattering. As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously explain the spectra observed by both CoGeNT and DAMA. The event rates in these experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass density. This abundance can arise directly from thermal freeze-out at weak coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal can be tested by searches for exotics in the BaBar and Belle datasets.