Comparing energy loss and p⊥-broadening in perturbative QCD with strong coupling N=4 SYM theory☆

Abstract We compare medium induced energy loss and p ⊥ -broadening in perturbative QCD with that of the trailing string picture of SYM theory. We consider finite and infinite extent matter as well as relativistic heavy quarks which correspond to those being produced in the medium or external to it. When expressed in terms of the appropriate saturation momentum, we find identical parametric forms for energy loss in perturbative QCD and SYM theory. We find simple correspondences between p ⊥ -broadening in QCD and in SYM theory although p ⊥ -broadening is radiation dominated in SYM theory and multiple scattering dominated in perturbative QCD.