From QCD to heavy ion collisions

This talk will discuss how heavy ion experiments, when moving from SPS (10 + 10 GeV) to RHIC (100+100 GeV) and to LHC (2750+2750 GeV), will enter a ne w domain of QCD in which the production of even large p(T) gluons is so abu ndant that it is simultaneously perturbative but such that the phase space density of gluons is saturated. The saturation scale p(sat) is estimated, q uantitative numbers for the initial production of gluons at the LHC are giv en and options for their subsequent evolution are outlined. For parametrica lly large nuclei and energies, classical field methods will be applicable.