Multijet Structure of High E_T Hadronic Collisions
  Multijet events at large transverse energy (sum E_T > 420 GeV) and large multijet invariant mass (M_jets > 600 GeV) have been studied by the CDF Collaboration at the Fermilab Tevatron. The observed jet multiplicity distribution can be understood in a QCD inspired exponentiation model, in regions of phase space which require going beyond fixed order perturbation theory. 
D. Rainwater, D. Summers, D. Zeppenfeld