High pT leading hadron suppression in nuclear collisions at sqrt(s_NN) = 20 -- 200 GeV: data versus parton energy loss models

Experimental results on high transverse momentum (leading) hadron spectra in nucleus-nucleus collisions in the range sqrt(s_NN) = 20 -- 200 GeV are reviewed with an emphasis on the observed suppression compared to free space production in proton-proton collisions at the corresponding center-of-mass energies. The transverse-momentum and collision-energy (but seemingly not the in-medium path length) dependence of the experimental suppression factors measured in central collisions is consistent with the expectations of final-state non-Abelian parton energy loss in a dense QCD medium.