Jet quenching in hot strongly coupled gauge theories simplified

Abstract

Theoretical studies of jet stopping in strongly-coupled QCD-like plasmas have used gauge-gravity duality to find that the maximum stopping distance scales like E^{1/3} for large jet energies E. In recent work studying jets that are created by finite-size sources in the gauge theory, we found an additional scale: the typical (as opposed to maximum) jet stopping distance scales like (EL)^{1/4}, where L is the size of the space-time region where the jet is created. In this paper, we show that the results of our previous, somewhat involved computation in the gravity dual, and the (EL)^{1/4} scale in particular, can be very easily reproduced and understood in terms of the distance that high-energy particles travel in AdS_5-Schwarzschild space before falling into the black brane. We also investigate how stopping distances depend on the conformal dimension of the source operator used to create the jet.

Comments: 30 pages, 10 figures