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Related papers: Re-running the QCD shear viscosity

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The shear viscosity of the quark-gluon plasma is predicted to be lower than the collisional viscosity for weak coupling. The estimated ratio of the shear viscosity to entropy density is rather close to the ratio calculated by N = 4 super…

Nuclear Theory · Physics 2014-03-19 Juhee Hong , P. H. Diamond

A discussion on the electrical conductivity of the quark-gluon plasma as determined by lattice QCD is given. After a reminder of basic definitions and expectations, various methods for spectral reconstruction are reviewed, including the use…

High Energy Physics - Lattice · Physics 2021-04-21 Gert Aarts , Aleksandr Nikolaev

Recently, it has been found that the kinematic viscosity of liquids at the minimum, $\nu_m$, can be expressed in terms of fundamental physical constants, giving $\nu_m$ on the order of $10^{-7}~{\rm m^2/s}$. Here, we show that the kinematic…

High Energy Physics - Theory · Physics 2021-05-31 Matteo Baggioli , Vadim Brazhkin , Kostya Trachenko

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ${\sim\,}150{-}350$ MeV. We use Bayesian inference to translate…

Through model-to-data comparisons from heavy-ion collisions, it has been shown that the Quark Gluon Plasma has an extremely small shear viscosity at vanishing densities. At large baryon densities, significantly less is known about the…

High Energy Physics - Phenomenology · Physics 2025-06-12 Isabella Danhoni , Jordi Salinas San Martin , Jacquelyn Noronha-Hostler

We consider corrections to the ratio of the shear viscosity to the entropy density in strongly coupled nonabelian plasmas using the AdS/CFT correspondence. In particular, higher derivative terms with the five-form RR flux, which have been…

High Energy Physics - Theory · Physics 2009-02-20 Robert C. Myers , Miguel F. Paulos , Aninda Sinha

The leading-order weak-coupling shear viscosity of QCD was computed almost 20 years ago, and the extension to next-to-leading order is 4 years old. But these results have never been applied at finite baryon chemical potential $\mu$, despite…

High Energy Physics - Phenomenology · Physics 2023-02-17 Isabella Danhoni , Guy D. Moore

The transport properties of the quark gluon plasma (QGP) are studied in a QCD medium at finite temperature and chemical potential. We calculate the shear viscosity $\eta(T,\mu_q)$ and the electric conductivity $\sigma_e(T,\mu_q)$ for a…

High Energy Physics - Phenomenology · Physics 2015-06-11 Hamza Berrehrah , Elena Bratkovskaya , Wolfgang Cassing , Rudy Marty

One of the most remarkable features of the Quark Gluon Plasma is its nearly perfect fluidity behavior indicated by the small shear viscosity to entropy density ratio obtained from fitting relativistic viscous hydrodynamics flow harmonics to…

Nuclear Theory · Physics 2015-12-22 Jacquelyn Noronha-Hostler

Shear and bulk viscosities of deconfined gluonic matter are investigated within an effective kinetic theory by describing the strongly interacting medium phenomenologically in terms of quasiparticle excitations with medium-dependent…

High Energy Physics - Phenomenology · Physics 2011-09-16 M. Bluhm , B. Kampfer , K. Redlich

Ultrarelativistic heavy-ion collisions at the Relativistic Heavy-Ion Collider (RHIC) are thought to have produced a state of matter called the Quark-Gluon-Plasma, characterized by a very small shear viscosity to entropy density ratio…

Nuclear Theory · Physics 2010-04-21 Nasser Demir , Steffen A. Bass

In order to describe properties of an equilibrated quark-gluon plasma, QCD at finite temperature (and density) has to be considered. Besides lattice calculations, which can be applied only to static quantities at zero density, perturbative…

High Energy Physics - Phenomenology · Physics 2009-10-31 Markus H. Thoma

The elliptic flow $v_2$ and the ratio of the shear viscosity over the entropy density, $\eta/s$, of gluon matter are calculated from the perturbative QCD (pQCD) based parton cascade Boltzmann approach of multiparton scatterings. For Au+Au…

Nuclear Theory · Physics 2008-11-26 Zhe Xu , Carsten Greiner , Horst Stoecker

A set of kinetic equations is used to study equilibration of the anisotropic quark-gluon plasma produced by decays of color flux tubes possibly created at the very early stages of ultra-relativistic heavy-ion collisions. The decay rates of…

High Energy Physics - Phenomenology · Physics 2013-08-28 Radoslaw Ryblewski , Wojciech Florkowski

We revisit the computation of the shear viscosity to entropy ratio $\eta/s$ at finite chemical potential in a holographic model that takes into account the quantum fluctuations in the IR region of near-extremal black branes. Such quantum…

High Energy Physics - Theory · Physics 2026-03-05 Sera Cremonini , Li Li , Xiao-Long Liu , Jun Nian

Using chiral perturbation theory we investigate the QCD shear viscosity to entropy density ratio below the deconfinement temperature (~170 MeV) with zero baryon number density. It is found that the viscosity to entropy density ratio of QCD…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jiunn-Wei Chen , Eiji Nakano

We study the thermal part of the energy density spatial correlator in the quark-gluon plasma. We describe its qualitative form at high temperatures. We then calculate it out to distances approx. 1.5/T in SU(3) gauge theory lattice…

High Energy Physics - Lattice · Physics 2009-11-13 Harvey B. Meyer

We propose a gauge-invariant and manifestly UV finite resummation of the physics of hard thermal/dense loops (HTL/HDL) in the thermodynamics of the quark-gluon plasma. The starting point is a simple, effectively one-loop expression for the…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. -P. Blaizot , E. Iancu , A. Rebhan

Substantial collective flow is observed in collisions between large nuclei at high energy, and the data are well-reproduced by perfect fluid dynamics. In a separate development, calculation of the dimensionless ratio of shear viscosity…

Nuclear Theory · Physics 2013-08-01 Joseph I. Kapusta

We review the proposal to resum the physics of hard thermal loops in the thermodynamics of the quark-gluon plasma through nonperturbative expressions for entropy and density obtained from a Phi-derivable two-loop approximation. A comparison…

High Energy Physics - Phenomenology · Physics 2017-08-23 Anton Rebhan