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Related papers: Shear Viscosity and Chern-Simons Diffusion Rate fr…

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We compute the bulk, $\zeta$, and shear, $\eta$, viscosity over entropy density, $s$, for the QCD matter formed in small collision systems at LHC. We consider a scenario of the String Percolation Model by proposing a global form of the…

High Energy Physics - Phenomenology · Physics 2023-12-06 J. R. Alvarado García , I. Bautista , A. Fernández Téllez , P. Fierro

We investigate $\eta/s$ in linear scalar fields modified Gauss-Bonnet theory that breaks translation invariance. We first calculate $\eta/s$ both analytically and numerically and show its relationship with temperature in log-log plot. Our…

High Energy Physics - Theory · Physics 2016-09-28 Yi-Li Wang , Xian-Hui Ge

We study the shear mode in the gauge/gravity correspondence at finite temperature. First, we confirm the general formula for the shear viscosity in an arbitrary background metric which includes a black hole in the fifth dimension. We then…

High Energy Physics - Theory · Physics 2008-11-26 J. I. Kapusta , T. Springer

Lattice calculations of the QCD trace anomaly at temperatures $T<160$ MeV have been shown to match hadron resonance gas model calculations, which include an exponentially rising hadron mass spectrum. In this paper we perform a more detailed…

Nuclear Theory · Physics 2013-05-30 Jacquelyn Noronha-Hostler , Jorge Noronha , Carsten Greiner

We investigate the temperature dependence of the shear viscosity to entropy density ratio $\eta/s$ using a piecewise linear parametrization. To determine the optimal values of the parameters and the associated uncertainties, we perform a…

We investigate QCD matter using the two-flavor PNJL model and find that the shear viscosity to entropy density ratio {\eta}/s reaches a minimum while the bulk viscosity {\zeta}/s peaks near the chiral crossover line, particularly at large…

General Physics · Physics 2025-04-29 Jingxu Wu , Yuwei Yin , Jianing Shi

The gravitational formfactor similar to shear viscosity is identified. In the time-like region it corresponds to the contribution of exotic hybrid meson. The exotic quantum numbers may be considered as a counterpart of dissipation in…

High Energy Physics - Phenomenology · Physics 2023-01-18 Oleg Teryaev

The temperature and density dependence of the relaxation times, thermal conductivity, shear viscosity and bulk viscosity for a hot and dense gas consisting of pions, kaons and nucleons have been evaluated in the kinetic theory approach. The…

Shear $\eta$ and bulk $\zeta$ viscosities are calculated in a quasiparticle model within a relaxation time approximation for pure gluon matter. Below $T_c$ the confined sector is described within a quasiparticle glueball model. Particular…

Nuclear Theory · Physics 2015-03-17 A. S. Khvorostukhin , V. D. Toneev , D. N. Voskresensky

Within the framework of finite temperature field theory this paper discusses the shear viscosity of hot QED plasma through Kubo formula at one-loop skeleton diagram level with a finite chemical potential. The effective widths(damping rates)…

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

In this work, the qualitative impact of the net baryochemical potential dependence of the shear viscosity to entropy density ratio $\eta/s$ in hydrodynamical simulations is studied. The effect of a predicted non-constant $\eta/s$($\mu_B$)…

High Energy Physics - Phenomenology · Physics 2022-11-23 Niklas Götz , Hannah Elfner

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

The ratio of shear viscosity ($\eta$) to entropy density ($s$) for an equilibrated system is investigated in intermediate energy heavy ion collisions below 100$A$ MeV within the framework of the Boltzmann-Uehling-Uhlenbeck (BUU) model .…

Nuclear Theory · Physics 2011-09-01 S. X. Li , D. Q. Fang , Y. G. Ma , C. L. Zhou

It is by now well known that the relativistic heavy-ion collisions at RHIC, BNL have produced a strongly interacting fluid with remarkable properties, among them the lowest ever observed ratio of the coefficient of shear viscosity to…

Nuclear Theory · Physics 2010-03-19 Rajeev S. Bhalerao

We calculate the ratio of the viscosity to the entropy density for both Bose and Fermi gases in the unitary limit using a new approach to the quantum statistical mechanics of gases based on the S-matrix. In the unitary limit the scattering…

Quantum Gases · Physics 2015-05-20 André LeClair

Electronic materials can sustain a variety of unusual, but symmetry protected touchings of valence and conduction bands, each of which is identified by a distinct topological invariant. Well-known examples include linearly dispersing…

Mesoscale and Nanoscale Physics · Physics 2020-04-29 Marianne Moore , Piotr Surowka , Vladimir Juricic , Bitan Roy

We demonstrate that measurements of rapidity differential anisotropic flow in heavy ion collisions can constrain the temperature dependence of the shear viscosity to entropy density ratio {\eta}/s of QCD matter. Comparing results from…

Nuclear Theory · Physics 2016-06-01 Gabriel Denicol , Akihiko Monnai , Bjoern Schenke

The electron shear viscosity due to Coulomb scattering of degenerate electrons by atomic nuclei throughout a magnetized neutron star crust is calculated. The theory is based on the shear viscosity coefficient calculated neglecting magnetic…

Solar and Stellar Astrophysics · Physics 2015-12-22 D. D. Ofengeim , D. G. Yakovlev

The determination of the shear viscosity is a central topic in various areas of modern physics. In particular, it is often necessary to evaluate the shear viscosity $\eta$ of fluids made up of more than one species, all interacting with…

High Energy Physics - Phenomenology · Physics 2025-12-15 Gabriele Parisi , Vincenzo Nugara , Salvatore Plumari , Vincenzo Greco

It was recently conjectured that the ratio of the shear viscosity to entropy density, $ \eta/ s$, for any fluid always exceeds $\hbar/(4 \pi k_B)$. This conjecture was motivated by quantum field theoretic results obtained via the AdS/CFT…

High Energy Physics - Theory · Physics 2008-11-26 Thomas D. Cohen