Dr
Abhijit Majumder
(Wayne State University)
8/16/12, 2:00 PM
Oral Presentation
The in-medium modification of a hard jet is reformulated to consider the process of a hard parton propagating through a finite sized QCD medium, held at a fixed high temperature and vanishing chemical potential. The process is factorized into a hard part representing the propagation and scattering of the parton, and a soft part representing the non-perturbative color field experienced by the...
Paul Romatschke
(FIAS Frankfurt)
8/16/12, 2:20 PM
Oral Presentation
Hydrodynamics predicts long-lived sound and shear waves.
Thermal fluctuations in these waves can lead to the diffusion of
momentum density, contributing to the shear viscosity and other
transport coefficients. Within viscous hydrodynamics in 3+1
dimensions, this leads to a positive contribution to the shear
viscosity, which is finite but inversely proportional to the
microscopic shear...
Peter Arnold
(University of Virginia)
8/16/12, 2:40 PM
Oral Presentation
Previous top-down studies of jet stopping in strongly-coupled QCD-like plasmas with gravity duals have been in the infinite 't Hooft coupling limit $\lambda \to \infty$. They have found that, though a wide range of jet stopping distances are possible depending on initial conditions, the maximum jet stopping distance $\ell_{\rm max}$ scales with energy as $E^{1/3}$ at large energy. But it has...
Krishna Rajagopal
(MIT)
8/16/12, 3:00 PM
Jets
Oral Presentation
A holographic calculation of the quenching of a beam of gluons with typical momenta q shining through strongly coupled quark-gluon plasma shows that such a beam is attenuated rapidly over a distance of order q^{1/3} (pi T)^{-4/3} as it propagates at the speed of light, shedding trailing sound waves with momenta of order (pi T). At larger and larger q, the trailing sound wave becomes less and...
Dr
Yacine Mehtar-Tani
(IPhT-Saclay)
8/16/12, 3:20 PM
Oral Presentation
The recent jet measurements at RHIC and the LHC have challenged the heavy-ion community to a better understanding of jet fragmentation in the presence of the Quark-Gluon-Plasma (QGP).
Jet fragmentation in vacuum is well described by perturbative QCD and is characterized by color coherence effects that lead to the angular ordering of successive branchings along the jet. To investigate the...
Dr
Robert Pisarski
(Brookhaven National Lab.)
8/16/12, 3:40 PM
QCD at finite temperature and density
Oral Presentation
An effective theory for the region near the critical temperature, the "semi"-QGP, has been developed. In QCD, this is dominated by the partial ionization of color, up to temperatures about 300 MeV. Using the effective model, the temperature dependence for the ratio of the shear viscosity, to the entropy, is computed. This predicts a sharp increase in this ratio between ~ 160 MeV and ~ 300 MeV.
