Speaker
Description
We present the first ever AdS/CFT calculation of $\hat{q}$ for a light quark jet as a function of position or, equivalently, time. Our result does not suffer from the gamma factor blow up of the usual time-independent AdS/CFT heavy quark setup and is qualitatively similar to, but about a factor of 2/3 larger than, the light flavor result from Liu, Rajagopal, and Wiedemann. Our findings can be immediately implemented into any $\hat{q}$-based energy loss model.
Our $\hat{q}$ derivation relies on our calculation of the average distance squared, $s^2(t)$, travelled by the endpoint of a string falling in an AdS$_3$-Schwarzschild spacetime. The early time behavior is ballistic, $s^2(t)\sim t^2$, but the late time behavior is the usual diffusive Brownian motion, $s^2(t)\sim t$. These late time dynamics are universal and depend only on the near-horizon physics, which allows us to generalize our results to arbitrary dimensions and thus make contact with the physics explored by RHIC and LHC.
Additionally, we find that AdS/CFT predicts angular ordering for radiation in medium, just as in vacuum, and in contradistinction to weak-coupling, with its anti-angular ordering prediction. Finally, our results also imply, sensibly, that AdS/CFT predicts a smooth interpolation between the angular correlations of open heavy flavor and light flavor observables.
Summary
The content is based on the R. W. Moerman and W. A. Horowitz arXiv:1605.09285 [hep-th] manuscript (currently under review at JHEP) and is appropriate for the "Jet production and modification in QCD matter" or, possibly, the "High pT hadron spectra and correlations" stream.
| Presentation type | Oral |
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