5.1 Nonphotonic electron predictions from the AdS/CFT drag and pQCD WHDG [152] models compared to$_{Rhic}$ data from$_{Phe-}$ nix [237, 238] and$_{Star}$ [239, 240] in central 200 GeV Au + Au collisions. For a density of dN$_{g}$/dy = 1000 the perturbative estimate is in qualitative disagreement; the drag calculation is in agreement in its range of reasonable choices of input param- eters. See text for details of the drag calculation; the electron fragmentation was done as in [152] . . . . . . . . . . . . . . . 120 xvii