Production of transverse energy from minijets in next-to-leading order perturbative QCD

We compute in next-to-leading order (NLO) perturbative QCD the transverse energy carried into the central rapidity unit of hadron or nuclear collisions by the partons freed in the few-GeV subcollisions. The formulation is based on a rapidity window and a measurement function of a new type. The behaviour of the NLO results as a function of the minimum transverse momentum and as a function of the scale choice is studied. The NLO results are found to be stable relative to the leading-order ones even in the few-GeV domain. Consequences of the NLO computation for the estimates of the final state charged particle multiplicity and transverse energy per unit rapidity in ultrarelativistic heavy ion collisions at RHIC and LHC are also studied. (C) 2000 Elsevier Science B.V. All rights reserved.