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Related papers: Shear Viscosity to Entropy within a Parton Cascade

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Within a covariant parton cascade, we discuss the impact of both finite shear viscosity $\eta$ and freeze-out dynamics on the elliptic flow generated at RHIC. We find that the enhancement of $\eta/s$ in the cross-over region of the QGP…

Nuclear Theory · Physics 2010-03-04 V. Greco , M. Colonna , M. Di Toro , G. Ferini

Elliptic flow measurements at RHIC suggest that quark gluon plasma flows with very little viscosity compared to weak coupling expectations, challenging theorists to explain why this fluid is so nearly ``perfect''. It is therefore vital to…

Nuclear Theory · Physics 2009-11-11 Sean Gavin , Mohamed Abdel-Aziz

Shear viscosity measures the amount of internal friction in a simple fluid. In kinetic theory shear viscosity is related to momentum transport by quasi-particles, and the uncertainty relation implies that the ratio of shear viscosity eta to…

Fluid Dynamics · Physics 2010-01-15 Thomas Schaefer

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

The shear ($\eta$) and bulk ($\zeta$) viscosities are calculated in a quasiparticle relaxation time approximation. The hadron phase is described within the relativistic mean field based model with scaled hadron masses and couplings. The…

Nuclear Theory · Physics 2010-10-19 A. S. Khvorostukhin , V. D. Toneev , D. N. Voskresensky

We report recent progress on causal viscous hydrodynamics for relativistic heavy ion collisions. For fixed specific shear viscosity eta/s, uncertainties in the elliptic flow arising from initial conditions, equation of state, bulk viscosity…

Nuclear Theory · Physics 2010-01-15 Huichao Song , Ulrich W. Heinz

One of the most striking results from the Relativistic Heavy Ion Collider is the strong elliptic flow. This review summarizes what is observed and how these results are combined with reasonable theoretical assumptions to estimate the shear…

Nuclear Theory · Physics 2016-12-21 Derek A. Teaney

We compute the shear viscosity, $\eta$, at general temperatures $T$, in a BCS-BEC crossover scheme which is demonstrably consistent with conservation laws. The study of $\eta$ is important because it constrains microscopic theories by…

Quantum Gases · Physics 2011-08-04 H. Guo , D. Wulin , C. C. Chien , K. Levin

We use the excluded volume Hadron Resonance Gas (HRG) model with the most up-to-date hadron list to calculate $\eta T/w$ at low temperatures and at finite baryon densities $\rho_B$. This $\eta T/w$ is then matched to a QCD-based shear…

High Energy Physics - Phenomenology · Physics 2022-02-16 Emma McLaughlin , Jacob Rose , Travis Dore , Paolo Parotto , Claudia Ratti , Jacquelyn Noronha-Hostler

The shear viscosity of liquid cobalt at the pressure $p=1.5$~bar and at the temperatures corresponding to equilibrium liquid and supercooled liquid states is measured experimentally and evaluated by means of molecular dynamics simulations.…

Materials Science · Physics 2018-06-07 R. M. Khusnutdinoff , A. V. Mokshin , A. L. Beltyukov , N. V. Olyanina

The shear viscosity of the quark-gluon plasma (QGP) plays a crucial role in interpreting current measurements from heavy-ion collisions and is a key input to hydro-dynamical models. The interest in shear viscosity also lies in the fact that…

High Energy Physics - Lattice · Physics 2025-10-31 Pavan , Olaf Kaczmarek , Guy D. Moore , Christian Schmidt

In the framework of irreversible thermodynamics, we studied the transport properties of QGP. Shear viscosity and non-equilibrium entropy density related to viscous process at finite density has been investigated in weakly coupled limit by…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hui Liu , Defu Hou , Jiarong Li

The ratio of shear viscosity to entropy density, $\eta/s$, is computed in various holographic geometries that break translation invariance (but are isotropic). The shear viscosity does not have a hydrodynamic interpretation in such…

High Energy Physics - Theory · Physics 2016-04-20 Sean A. Hartnoll , David M. Ramirez , Jorge E. Santos

It is proposed that a study of the ratio of shear viscosity to entropy density $\frac{\eta}{s}$ as a function of the baryon chemical potential $\mu_B$, and temperature T, provides a dynamic probe for the critical end point (CEP) in hot and…

Nuclear Experiment · Physics 2008-05-09 Roy A. Lacey , N. N. Ajitanand , J. M. Alexander , P. Chung , J. Jia , A. Taranenko , P. Danielewicz

We calculate the shear viscosity $\eta$ in the quark-gluon plasma (QGP) phase within a virial expansion approach with particular interest in the ratio of $\eta$ to the entropy density $s$, i.e. $\eta/s$. The virial expansion approach allows…

High Energy Physics - Phenomenology · Physics 2011-02-09 S. Mattiello , W. Cassing

The specific shear viscosity $\bar\eta$ of a classically rotating system of nucleons that interact via a monopole pairing interaction is calculated including the effects of thermal fluctuations and coupling to pair vibrations within the…

Nuclear Theory · Physics 2015-06-05 N. Quang Hung , N. Dinh Dang

In the Beam Energy Scan phase II (BES-II) experiments at RHIC STAR, the quark-gluon plasma (QGP) produced with changing collision energies may probe different regions of the QCD phase diagram. Correspondingly, studying the transport…

High Energy Physics - Phenomenology · Physics 2025-12-01 Wei-be He , Guo-yun Shao , Chong-long Xie , Ren-xin Xu

We have explored the shear viscosity and electrical conductivity calculations for bosonic and fermionic medium, which goes from without to with magnetic field picture and then their simplified massless expressions. In presence of magnetic…

High Energy Physics - Phenomenology · Physics 2020-10-12 Jayanta Dey , Sarthak Satapathy , Prasanta Murmu , Sabyasachi Ghosh

The shear viscosity $\eta$ of a quark-gluon plasma in equilibrium can be calculated analytically using multiple methods or numerically using the Green-Kubo relation. It has been realized, which we confirm here, that the Chapman-Enskog…

Nuclear Theory · Physics 2022-10-27 Noah M. MacKay , Zi-Wei Lin

We present the first ab initio determination of the shear viscosity eta of the Unitary Fermi Gas, based on finite temperature quantum Monte Carlo calculations and the Kubo linear-response formalism. We determine the temperature dependence…

Quantum Gases · Physics 2012-07-16 Gabriel Wlazłowski , Piotr Magierski , Joaquín E. Drut