TRANSVERSE-MOMENTUM DISTRIBUTION OF Z-BOSON PAIRS AT HADRON SUPERCOLLIDERS

We present the transverse-momentum distribution of the Z-pairs for pp --> ZZX at supercollider energies. The full p(T)(ZZ) spectrum is obtained by matching the low-p(T) result (from soft gluon resummation to all orders in alpha(s)) to the high-p(T) result (from the O(alpha(s)) perturbative calculation). We examine where the fixed O(alpha(s)) perturbative calculation is unreliable. We also present a comparison of our result with the Monte Carlo program PYTHIA. The results are significant for background calculations to heavy Higgs boson searches at hadron supercolliders, as well as for testing perturbative QCD.