WIMPless Dark Matter from an AMSB Hidden Sector

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 NF 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 ΔNeff ∼ 0 - 2, and, if the hidden and visible sectors were initially in thermal contact, the model predicts ΔNeff ∼ 0.2 - 0.4. Data already taken by Planck may provide evidence of such deviations.