X iv : h ep - t h / 06 10 17 9 v 2 1 5 Ja n 20 07 Drag force in a string model dual to large - N QCD Pere Talavera

1 5 Ja n 20 07 Drag force in a string model dual to large - N QCD

Drag force in a string model dual to large-N QCD

We compute the drag force exerted on a quark and a di-quark systems in a background dual to large-N QCD at finite temperature. We find that appears a drag force in the former setup with flow of energy proportional to the mass of the quark while in the latter there is no dragging as in other studies. We also review the screening length.

ar X iv : h ep - t h / 06 12 12 9 v 3 1 1 Ja n 20 07 STRING COSMOLOGY

ar X iv : h ep - p h / 00 09 23 7 v 3 2 9 Ja n 20 01 “ Bottom - up ” thermalization in heavy ion collisions

We describe how thermalization occurs in heavy ion collisions in the framework of perturbative QCD. When the saturation scale Q s is large compared to Λ QCD , thermalization takes place during a time of order α −13/5 Q −1 s and the maximal temperature achieved is α 2/5 Q s .

ar X iv : h ep - t h / 06 05 23 5 v 1 2 3 M ay 2 00 6 Drag Force in a Charged N = 4 SYM Plasma

Following recent developments, we employ the AdS/CFT correspondence to determine the drag force exerted on an external quark that moves through an N = 4 super-Yang-Mills plasma with a non-zero R-charge density (or, equivalently, a non-zero chemical potential). We find that the drag force is larger than in the case where the plasma is neutral.