Holography of radiation and jet quenching

Abstract

We study the non-linear propagation of radiation in N=4 SYM at zero and finite temperature using the refined radius/scale duality in AdS/CFT. We argue that a pulse radiation by a quark at the boundary should be described holographically by a "point like object" passing through the center of the AdS bulk. We find that at finite temperature, the radiation stalls at a distance of 1/πT with a natural geometric and holographic interpretation. Indeed, the stalling is the holographic analogue of the gravitational in-fall of light towards the black hole in the bulk. We suggest that these results are relevant for jet quenching by a strongly coupled quark-gluon liquid as currently probed in heavy ion colliders at RHIC. In particular, colored jets cannot make it beyond 1/3 fm at RHIC whatever their energy.

Universality of the diffusion wake in the gauge-string duality

“…The dashed green line marks the Mach angle, and the gray line marks the curve where the far field asymptotics of the wake falls to half its maximal value. [10,11,12,13,14,15,16,17]. We note in particular the close relation of [12] to the drag force results of [3,4].…”

Anisotropic plasma at finite U(1) chemical potential

“…The dual anisotropic holographic fermions will be investigated. The jet quenching parameter, the drag force and heavy quark energy loss [95][96][97][98] due to the anisotropic effects at finite U(1) chemical potential will also be studied. The study on transport coefficients of the dual anisotropic hydrodynamics, in particular the conductivity and shear viscosity are also in progress.…”

Momentum fluctuations of heavy quarks in the gauge-string duality

“…An intuitive way to see this is that a point on the trailing string with y held fixed follows a timelike trajectory if y < y S and a spacelike one if y > y S . 4 So the region y < y S corresponds to the exterior of the "black hole on the worldsheet," and y > y S corresponds to the interior. No signal from the interior can propagate classically to the exterior.…”

“…Earlier work in a somewhat similar spirit includes [4]. Independently, a proposal was made in [5] for extracting the jet-quenching parameterq for N = 4 gauge theory from a Wilson loop calculation amenable to solution through techniques of classical string theory.…”