Non-perturbative computation of gluon mini-jet production in nuclear collisions at very high energies

At very high energies, in the infinite momentum frame and in light-cone gauge, a hard scale proportional to the high parton density arises in QCD. In an effective theory of QCD at small x, this scale is of order alpha s mu, where mu is simply related to the gluon density at higher rapidities. The ab initio real time evolution of small x modes in a nuclear collision can be described consistently in the classical effective theory and various features of interest can be studied non-perturbatively. In this paper, we discuss results from a real time SU(2) lattice computation of the production of gluon jets at very high energies. At very large transverse momenta, k(t) greater than or equal to mu, OUT results match the predictions from pQCD based mini-jet calculations. Novel non-perturbative behavior of the small x modes is seen at smaller momenta k(t) similar to alpha s mu. Gauge invariant energy-energy correlators are used to estimate energy distributions evolving in proper time. (C) 1999 Elsevier Science B.V. All rights reserved.