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Related papers: Shear viscosity from Kubo formalism: NJL-model stu…

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The branching fraction of the decay $\eta' \to \pi\rho$ is calculated in the chiral quark NJL model. The decay exists due to the mass difference between $u$- and $d$-quarks leading to $\pi^{0}-\eta^{'}$ mixing. Two different approaches are…

High Energy Physics - Phenomenology · Physics 2022-11-29 M. K. Volkov , A. A. Pivovarov , K. Nurlan

The properties of strong-interaction matter are probed in ultra-relativistic heavy-ion collisions. In the context of measurements of the elliptic flow at RHIC and the LHC the shear viscosity is of particular interest. In this presentation…

High Energy Physics - Phenomenology · Physics 2015-06-03 J. Wambach , K. Heckmann , M. Buballa

We show that first approximations to the bulk viscosity $\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of…

Nuclear Theory · Physics 2009-11-18 A. Wiranata , M. Prakash

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

We calculate the shear viscosity over entropy density ratio $\eta/s$ in Yang--Mills theory from the Kubo formula using an exact diagrammatic representation in terms of full propagators and vertices using gluon spectral functions as external…

High Energy Physics - Phenomenology · Physics 2015-09-16 Nicolai Christiansen , Michael Haas , Jan M. Pawlowski , Nils Strodthoff

We derive an expression relating the transport parameter $\hat{q}$ and the shear viscosity $\eta$ of a weakly coupled quark-gluon plasma. A deviation from this relation can be regarded as a quantitative measure of ``strong coupling'' of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Majumder , B. Müller , X. -N. Wang

In this work we have presented the one-loop calculation of the bulk viscosity of a system of rotating, hot and dense spin 1/2 fermions within the framework of Kubo formalism calculated from correlation functions of fields which in turn is…

Nuclear Theory · Physics 2023-11-13 Sarthak Satapathy

A two-flavor color superconducting (2SC) Nambu--Jona-Lasinio (NJL) model is introduced at finite temperature T, chemical potential mu and in the presence of a constant magnetic field eB. The effect of (T,mu,eB) on the formation of chiral…

High Energy Physics - Phenomenology · Physics 2015-03-17 Sh. Fayazbakhsh , N. Sadooghi

The thermodynamic characteristics of hot $\beta$-equilibrium three-flavor quark matter with neutrino confinement are studied in terms of the local SU(3) Nambu-Jona-Lasinio (NJL) model, which also accounts for the 't Hooft interaction which…

Nuclear Theory · Physics 2022-08-17 G. S. Hajyan , G. B. Alaverdyan

The rich phenomena of the shear viscosity (eta) to entropy density (s) ratio, eta/s, in weakly coupled N-component scalar field theories are studied. eta/s can have a "double dip" behavior due to resonances and the phase transition. If an…

High Energy Physics - Phenomenology · Physics 2011-06-24 Jiunn-Wei Chen , Mei Huang , Chang-Tse Hsieh , Han-Hsin Lin

We have gone through a comparative study on two different kind of bulk viscosity expressions by using a common dynamical model. The Polyakov-Nambu-Jona-Lasinio (PNJL) model in the realm of mean-field approximation, including up to eight…

High Energy Physics - Phenomenology · Physics 2017-01-10 Kinkar Saha , Sudipa Upadhaya , Sabyasachi Ghosh

A short review of the development of the Nambu-Jona-Lasinio (NJL) model is given. The SU(2)x SU(2) and U(3)x U(3) local quark NJL models are considered. The mechanisms of spontaneous breaking of chiral symmetry and vector dominance are…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. K. Volkov , A. E. Radzhabov

In this paper, we conduct a thorough investigation of the surface and curvature tensions, $\sigma$ and $\gamma$, of three-flavor cold quark matter using the Nambu-Jona-Lasinio (NJL) model with vector interactions. Our approach ensures both…

Nuclear Theory · Physics 2024-07-09 A. G. Grunfeld , M. F. Izzo Villafañe , G. Lugones

We analyze the thermodynamical properties of a system of strongly interacting particles at vanishing quark chemical potential in the framework of a recently developed extension of the Polyakov-Nambu-Jona-Lasinio Model. In addition to eight…

High Energy Physics - Phenomenology · Physics 2020-01-08 J. Moreira , J. Morais , B. Hiller , A. H. Blin , A. A. Osipov

The bulk viscosity of two-component fermions with a zero-range interaction is revisited both in two and three dimensions. We first point out that the "standard" Kubo formula employed in recent studies has flaws to give rise to an unphysical…

Quantum Gases · Physics 2020-08-13 Keisuke Fujii , Yusuke Nishida

We study the transport properties of strongly interacting matter in the context of ultrarelativistic heavy ion collision experiments. We calculate the transport coefficients viz. shear viscosity ($\eta$) and electrical conductivity…

High Energy Physics - Phenomenology · Physics 2017-06-01 Lata Thakur , P. K. Srivastava , Guru Prakash Kadam , Manu George , Hiranmaya Mishra

Employing an extended three flavor version of the NJL model we discuss in detail the phase diagram of quark matter. The presence of quark as well as of diquark condensates gives raise to a rich structure of the phase diagram. We study in…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Gastineau , R. nebauer , J. Aichelin

In this paper we address the ratio of the shear viscosity to entropy density $\eta/s$ in bosonic and fermionic superfluids. A small $\eta/s$ is associated with nearly perfect fluidity, and more general measures of the fluidity…

Quantum Gases · Physics 2015-06-22 Rufus Boyack , Hao Guo , K. Levin

The electrical conductivity of hot and dense quark matter is calculated using the 2-flavour gauged Nambu-Jona--Lasinio (NJL) model in the presence of a chiral imbalance quantified in terms of a chiral chemical potential (CCP). To this end,…

High Energy Physics - Phenomenology · Physics 2024-12-30 Snigdha Ghosh , Nilanjan Chaudhuri , Sourav Sarkar , Pradip Roy

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