WIMPless Dark Matter in Anomaly-Mediated Supersymmetry Breaking with Hidden QED

TL;DR

This paper proposes a simple model of WIMPless dark matter within anomaly-mediated supersymmetry breaking, featuring multi-component hidden sector particles that could produce observable self-interactions and deviations in relativistic degrees of freedom.

Contribution

It introduces a minimal hidden sector model with supersymmetric QED that naturally yields the correct dark matter relic density and predicts observable effects in cosmological data.

Findings

Hidden sector particles can have masses from 10 GeV to 10 TeV.

Hidden photons contribute to ff in the range 0-2.

Model predicts ff deviations of 0.2-0.4 detectable by Planck.

Abstract

In anomaly-mediated supersymmetry breaking, superpartners in a hidden sector have masses that are proportional to couplings squared, and so naturally freeze out with the desired dark matter relic density for a large range of masses. We present an extremely simple realization of this possibility, with WIMPless dark matter arising from a hidden sector that is supersymmetric QED with N_F flavors. Dark matter is multi-component, composed of hidden leptons and sleptons with masses anywhere from 10 GeV to 10 TeV, and hidden photons provide the thermal bath. The dark matter self-interacts through hidden sector Coulomb scatterings that are potentially observable. In addition, the hidden photon contribution to the number of relativistic degrees of freedom is in the range \Delta N_eff ~ 0 - 2, and, if the hidden and visible sectors were initially in thermal contact, the model predicts \Delta N_eff ~ 0.2 - 0.4. Data already taken by Planck may provide evidence of such deviations.