Single Z Production at the Tevatron
  The production of single $Z$ bosons has been studied at Fermilab's Tevatron by the CDF and D0 collaborations. Measurements include the weak mixing angle, vector and axial-vector couplings between $Z$ bosons and light quarks, and angular coefficients in electronic decays which are sensitive to the spin of the gluon. The collaborations have looked for and indication of new physics above the mass scale that can be directly produced at the Tevatron by studying the interference between $Z$ and photon propagators. All measurements are consistent with Standard Model expectations. 
Thomas J. Phillips
hep-ex