Bulk viscosity of high-temperature QCD

By P. Arnold, Çağlar Doğan, Guy D. Moore. 2006

214 citations recorded by the source corpus.

We compute the bulk viscosity {zeta} of high-temperature QCD to leading order in powers of the running coupling {alpha}{sub s}(T). We find that it is negligible compared to shear viscosity {eta} for any {alpha}{sub s} that might reasonably be considered small. The physics of bulk viscosity in QCD is a bit different than in scalar {phi}{sup 4} theory. In particular, unlike in scalar theory, we find that an old, crude estimate of {zeta}{approx_equal}15((1/3)-v{sub s}{sup 2}){sup 2}{eta} gives the correct order of magnitude, where v{sub s} is the speed of sound. We also find that leading-log expansions of our result for {zeta} are not accurate except at very small coupling.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e7db7350191175f6a8722fa6b43ec95baafabc35

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In Nuclear and High Energy Physics

Citations in the corpus

Thermal transport and drag force in improved holographic QCD (2009, unknown): “However, the T-dependence is very similar to the pQCD result, [54]: ζ/s ∝ log(πT/Λ) log log(πT/Λ) .”
Properties of hot and dense matter from relativistic heavy ion collisions (2015, background): “Perturbative corrections to this result are computable and start at O(α s) [83, 84].”
Transport properties of the quark-gluon plasma (2011, methodology): “he shear and bulk viscosities The conductivity, as well as the shear and bulk viscosities, have been obtained beyond the leading-logarithmic order, namely to full leading order in the gauge coupling g[15,68]. The method follows the steps sketched in the previous section, namely a Boltzmann equation ”
Improved Holographic QCD (2010, unknown): “We note however, that the asymptotic T-dependence is very similar to the pQCD result, [75]: ζ/s ∝ log−2(πT/Λ) log−1 log(πT/Λ) .”
Bulk viscosity of QCD matter near the critical temperature (2007, background): “One can see that away from Tc the bulk viscosity is small, in accord with the expectations based on the perturbative results [15].”
Relativistic Fluid Dynamics in and out of Equilibrium (2017, methodology): “ 1 3 (1 23c s ) ˘ 2 2˝ ˇc 2 s 3 (1 3c2 s ) ˘ 3 3 3 (1 3c2 s ) Ref. [128] ˘ 4 0 Ref. [128] ˘ 5 3 (1 3c2 s ) c2 6 (1 3c2) ˘ 6 3c2 s (1 3c2 s ) Ref. [128] Refs. [54, 139, 140] [117, 118, 141] [67, 128, 142] [143{145] Table 2.2: Compilation of non-conformal transport coecient results in various calc”
Dissipation coefficients from scalar and fermion quantum field interactions (2010, background): “In the high-temperature regime, however, computation of the dissipation coefficients are known to have issues regarding resummation of higher loop terms [21–23].”
Primordial gravitational waves, precisely: the role of thermodynamics in the Standard Model (2018, methodology): “rection is negligible as long as ˛H. Furthermore, it is generically expected that the bulk viscosity coecient is much smaller than the shear viscosity coecient ˘ˆ= for high temperature radiations [45], and the net eect can be further suppressed. For these reasons, we can safely neglect the correctio”