model is D = 2 / √ λπT ∗ [351]. This illustrates well the problem of connecting the T ∗ and λ of SYM to “our” QCD world. Using the “obvious” prescription with α$_{s}$ = . 3, N$_{c}$ = 3, one finds D ∼ 1 . 2 / 2 πT . However, D = 3 / 2 πT was claimed in [351, 424] to fit Phenix data somewhat better. Note that D = 3 / 2 πT requires an unnaturally small α$_{s}$ ∼ 0 . 05 that is very far from the assumed λ ≫ 1 ’t Hooft limit. 

We proceed by computing the charm and bottom nuclear modification factors, neglecting initial state shadowing or saturation effects. In order to correctly deconvolute such effects from the final state effects that we compute below, it will be necessary to measure nuclear modification factors in p + A as a function of ( y, p$_{T}$ ) at Lhc just as d + A was the critical control experiment [77] at Rhic [104]. 

Final state suppression of high- p$_{T}$ jets due to a fractional energy loss ϵ , p f T = (1 − ϵ ) p i $_{T}$, can be computed knowing the Q -flavor dependent spectral indices n$_{Q}$ +1 = − d d log p$_{T}$ log ( dσ$_{Q}$ dydp$_{T}$ $^{)}$from pQCD or directly from p + p → Q + X data. The nuclear modification factor is then R Q $_{AA}$( p$_{T}$ ) = < (1 − ϵ ) n$_{Q}$ > , where the average is over the distribution P ( ϵ ; M$_{Q}$, p$_{T}$ , ℓ ) that depends in general on the quark mass, p$_{T}$ , and the path length ℓ of the jet through the sQGP. As in [152] we find n$_{Q}$ from FONLL production cross sections [381, 388], average over jets produced according to the binary distribution geometry, and compute ℓ through a participant transverse density distribution taking into account the nuclear diffuseness. Given dN/dy of midrapidity partons, the temperature is computed assuming isentropic Bjorken 1 D Hubble flow (see Appendix C) with 

