Direct photon spectra (top) and direct photon excess \Rgamma (bottom) measured in \PbPb\ collisions at \sqrtSnn = 2.76 TeV  and \sqrtSnn = 0.2 TeV  in the 0--20\% (left) and 20--40$\%$ (right) centrality classes. The slope of the exponential function fitted to the ALICE data was determined without subtracting any pQCD contribution. The slope of the spectrum measured by PHENIX was determined after subtracting a pQCD contribution determined by parameterising a direct photon measurement in pp collisions.