Abstract
We give an updated overview of both weak and strong coupling methods to describe the approach to a plasma described by viscous hydrodynamics, a process now called hydrodynamisation. At weak coupling the very first moments after a heavy ion collision is described by the colour-glass condensate framework, but quickly thereafter the mean free path is long enough for kinetic theory to become applicable. Recent simulations indicate thermalization in a time $t\sim40(\eta/s)^{4/3}/T$ [1], with $T$ the temperature at that time and $\eta/s$ the shear viscosity divided by the entropy density. At (infinitely) strong coupling it is possible to mimic heavy ion collisions by using holography, which leads to a dual description of colliding gravitational shock waves. The plasma formed hydrodynamises within a time of $0.41/T$. A recent extension found corrections to this result for finite values of the coupling, when $\eta/s$ is bigger than the canonical value of $1/4\pi$, which leads to $t\sim(0.41+1.6(\eta/s-1/4\pi))/T$ [2]. Future improvements include the inclusion of the effects of the running coupling constant in QCD.
Original language | Undefined/Unknown |
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Pages (from-to) | 74-80 |
Journal | Nuclear Physics A |
Volume | 967 |
DOIs | |
Publication status | Published - 1 Nov 2017 |
Bibliographical note
7 pages, 4 figures, talk presented at Quark Matter 2017 (Chicago)Keywords
- hydrodynamisation
- holography