Z^′-Mediated Supersymmetry Breaking

We consider a class of models in which supersymmetry breaking is communicated dominantly via a U(1)^′ gauge interaction, which also helps solve the μ problem. Such models can emerge naturally in top-down constructions and are a version of split supersymmetry. The spectrum contains heavy sfermions, Higgsinos, exotics, and Z^′∼10–100  TeV, light gauginos∼100–1000  GeV, a light Higgs boson∼140  GeV, and a light singlino. A specific set of U(1)^′ charges and exotics is analyzed, and we present five benchmark models. The implications for the gluino lifetime, cold dark matter, and the gravitino and neutrino masses are discussed.