A Chiral Supersymmetric Standard Model

We propose a supersymmetric extension of the Standard Model with an extra U(1) gauge symmetry, so that all supersymmetric mass terms, including the $\mu$-term, are forbidden by the gauge symmetries. Supersymmetry is broken dynamically which results in U(1) breaking and generation of realistic $\mu$ term and soft breaking masses. The additional fields required to cancel the U(1) anomalies are identified with the messengers of supersymmetry breaking. The gaugino masses arise as in the usual gauge mediated scenario, while squarks and sleptons receive their masses from both the U(1) $D$-term and the two-loop gauge mediation contributions. The scale of supersymmetry breaking in this model can be below $10^6$ GeV, yielding collider signatures with decays to goldstinos inside the detector.