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arXiv · hep-th/0701123

Transverse Momentum Broadening of a Fast Quark in a $\N=4$ Yang Mills Plasma

Jorge Casalderrey-Solana·Derek Teaney
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Abstract

We compute the momentum broadening of a heavy fundamental charge propagating through a $\mathcal{N}=4$ Yang Mills plasma at large t' Hooft coupling. We do this by expressing the medium modification of the probe's density matrix in terms of a Wilson loop averaged over the plasma. We then use the AdS/CFT correspondence to evaluate this loop, by identifying the dual semi-classical string solution. The calculation introduces the type ``1'' and type ``2'' fields of the thermal field theory and associates the corresponding sources with the two boundaries of the AdS space containing a black hole. The transverse fluctuations of the endpoints of the string determine $κ_T = \sqrt{γλ} T^3 π$ -- the mean squared momentum transfer per unit time. ($γ$ is the Lorentz gamma factor of the quark.) The result reproduces previous results for the diffusion coefficient of a heavy quark. We compare our results with previous AdS/CFT calculations of $\hat{q}$.

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Jorge Casalderrey-Solana, Derek Teaney. 2007-01-23. Transverse Momentum Broadening of a Fast Quark in a $\N=4$ Yang Mills Plasma. https://doi.org/10.1088/1126-6708%2F2007%2F04%2F039

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