Light quark energy loss in strongly-coupled N = 4 supersymmetric   Yang-Mills plasma
  We compute the penetration depth of a light quark moving through a large $N_c$, strongly coupled $\mathcal N = 4$ supersymmetric Yang-Mills plasma using gauge/gravity duality and a combination of analytic and numerical techniques. We find that the maximum distance a quark with energy $E$ can travel through a plasma is given by $\Delta x(E) = (\mathcal C/T) (E/T \sqrt\lambda)^{{1}/{3}}$ with $\mathcal C \approx 0.5$. 
Paul M. Chesler, Kristan Jensen, Andreas Karch, Laurence G. Yaffe