Gluon production in current-nucleus and nucleon-nucleus collisions in a quasi-classical approximation

We calculate gluon production in deep inelastic scattering of the current j = −14FμνaFμνa off a large nucleus and in nucleon-nucleus collisions. In a covariant gauge calculation the transverse momentum spectrum of the gluon is determined by the final state interactions of the gluon with the nucleons in the nucleus. In a light-cone gauge calculation final state interactions are absent and these effects come from the light-cone wavefunction of the nucleus. We work in an approximation which neglects QCD evolution of gluons in the nucleon, that is in a quasi-classical approximation.