Testing pQCD and AdS/CFT Energy Loss at RHIC and LHC

We compare calculations of jet quenching observables at root s = 2.76 ATeV to preliminary LHC data from weak-coupling pQCD and strong-coupling AdS/CFT drag energy loss models constrained to root s = 200 AGeV RHIC data. While somewhat overpredicting the suppression of hadrons, the pQCD-based WHDG model reproduces the hadron azimuthal anisotropy (over many centrality classes) and the suppression of D mesons at LHC. The drag predictions shown here compare poorly to the suppression of D mesons, but the current experimental uncertainties are large. The double ratio of D to B meson R-AA(p(T)) should provide a robust experimental measurement to distinguish between the very different assumptions of the strength of interactions in the QGP produced in heavy ion collisions; i.e., whether, from a jet quenching standpoint, the medium is either weakly- or strongly-coupled.