A Model of Direct Gauge Mediation of Supersymmetry Breaking

We present the first phenomenologically viable model of gauge meditation of supersymmetry breaking without a messenger sector or gauge singlet fields. The standard model gauge groups couple directly to the sector which breaks supersymmetry dynamically. Despite the direct coupling, it can preserve perturbative gauge unification thanks to the inverted hierarchy mechanism. There is no dangerous negative contribution to $m_{\tilde{q}}^2$, $m_{\tilde{l}}^2$ due to two-loop renormalization group equation. The potentially nonuniversal supergravity contribution to $m_{\tilde{q}}^2$ and $m_{\tilde{l}}^2$ can be suppressed enough. The model is completely chiral, and one does not need to forbid mass terms for the messenger fields by hand. Cosmology of the model is briefly discussed.