Production of Z Boson Pairs via Gluon Fusion in the Minimal   Supersymmetric Model
  We present the full one-loop calculation for $gg \to ZZ$ in the Minimal Supersymmetric Model (MSSM) including nonresonant contributions from the squark loop diagrams and provide analytical expressions for the helicity amplitudes. The one-loop process $gg \to ZZ$ via quark loops has been calculated in the Standard Model. In supersymmetric models, additional contributions arise from squark loops. In some regions of the MSSM parameter space, the top and bottom squark loops can make important contributions to the diagrams involving Higgs bosons. The heavy Higgs scalar (H) might be detected at the Large Hadron Collider via $gg \to H \to ZZ$ for $\tan\beta \alt 5$. 
M.S. Berger and Chung Kao