131 Chapter 5: pQCD vs. AdS/CFT charm and bottom R$_{AA}$ ( p$_{T}$ ) at $_{Lhc}$. Figure 5.4: The power law production index n$_{Q}$ ( p$_{T}$ ) for Rhic and $_{Lhc}$. While it is quite flat–but slowly increasing–over a large momentum range at $_{Lhc}$, at Rhic n$_{Q}$ ( p$_{T}$ ) hardens appreciably as momentum increases. 5.3 Double Ratio of charm to bottom R Q AA A disadvantage of the R Q $_{AA}$( p$_{T}$ ) observable alone is that its normalization and slow p$_{T}$ dependence can be fit with different model assumptions compensated by using very different medium parameters. In particular, high value ex- trapolations of the ˆ q parameter proposed in [435] could simulate the flat p$_{T}$ - independent prediction from AdS/CFT. We propose to use the double ratio of charm to bottom R$_{AA}$ to amplify the