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Related papers: Pion Gas Viscosity

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By using Chiral Perturbation Theory and the Uehling-Uhlenbeck equation we compute the viscosity of a pion gas, in the low temperature and low density regime, in terms of the temperature, and the pion fugacity. The viscosity turns out to be…

High Energy Physics - Phenomenology · Physics 2009-11-07 Antonio Dobado , Silvia N. Santalla

We report a calculation of the shear viscosity in a relativistic multicomponent meson gas as a function of temperature and chemical potentials. We approximately solve the Uehling-Uhlenbeck transport equation of kinetic theory, appropriate…

High Energy Physics - Phenomenology · Physics 2009-11-10 Antonio Dobado , Felipe J. Llanes-Estrada

We evaluate the heat conductivity of a dilute pion gas employing the Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by means of the SU(2) Inverse Amplitude Method. Our results are consistent with previous…

High Energy Physics - Phenomenology · Physics 2007-05-23 Antonio Dobado Gonzalez , Felipe J. Llanes-Estrada , Juan M. Torres Rincon

We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing…

High Energy Physics - Phenomenology · Physics 2011-07-19 Egang Lu , Guy D. Moore

We have evaluated the shear viscosity of pion gas taking into account its scattering with the low mass resonances, $\sigma$ and $\rho$ during propagation in the medium. The thermal width (or collisional rate) of the pions is calculated from…

Nuclear Theory · Physics 2014-04-08 Sabyasachi Ghosh , Gastão Krein , Sourav Sarkar

We investigate the shear viscosity of a pion gas in relativistic kinetic theory, using the Nambu-Jona-Lasinio model to construct the pion mass and the pi-pi interaction at finite temperature. Whereas at low temperatures the scattering…

High Energy Physics - Phenomenology · Physics 2012-11-07 Klaus Heckmann , Michael Buballa , Jochen Wambach

The bulk and shear viscosities of a pion gas is obtained by solving the relativistic transport equation in the Chapman-Enskog approximation. In-medium effects are introduced in the $\pi\pi$ cross-section through one-loop self-energies in…

High Energy Physics - Phenomenology · Physics 2013-05-30 Sukanya Mitra , Sourav Sarkar

We have calculated the shear viscosity of pion medium, where propagating pion has some finite thermal width due to interaction with the low mass resonances, $\sigma$ and $\rho$. With the help of standard thermal field theoretical technique,…

Nuclear Theory · Physics 2017-09-12 Sabyasachi Ghosh , Gastao Krein , Saurav Sarkar

We evaluate the shear viscosity of a pion gas in the relativistic kinetic theory approach. The in-medium propagator of the $\rho$ meson at finite temperature is used to evaluate the $\pi-\pi$ scattering amplitude in the medium. The real and…

Nuclear Theory · Physics 2012-07-26 Sukanya Mitra , Sabyasachi Ghosh , Sourav Sarkar

The steps essentially involved in the evaluation of transport coefficients in linear response theory using Kubo formulas are to relate the defining {\em retarded} correlation function to the corresponding {\em time-ordered} one and to…

Nuclear Theory · Physics 2013-08-09 Sourav Sarkar

We evaluate the ratio of shear viscosity to entropy density in a pion gas employing the Uehling-Uehlenbeck equation and experimental phase-shifts parameterized by means of the SU(2) Inverse Amplitude Method. We find that the ratio for this…

High Energy Physics - Phenomenology · Physics 2008-11-26 Antonio Dobado , Felipe J. Llanes-Estrada

We estimate the shear and the bulk viscous coefficients for a hot hadronic gas mixture constituting of pions and nucleons. The viscosities are evaluated in the relativistic kinetic theory approach by solving the transport equation in the…

Nuclear Theory · Physics 2017-03-13 Utsab Gangopadhyaya , Snigdha Ghosh , Sukanya Mitra , Sourav Sarkar

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature. We introduce a pion chemical potential to describe the finite pion number density and argue that such description is valid during the…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Ayala , P. Amore , A. Aranda

Within the finite-temperature Greens-function formalism we study the equation of state of a hot interacting pion gas at zero chemical potential. Employing realistic $\pi\pi$ meson-exchange interactions we selfconsistently calculate the…

Nuclear Theory · Physics 2008-11-26 R. Rapp , J. Wambach

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…

Based on a recent meson-exchange model for the vacuum $\pi\pi$ interaction we compute selfconsistently the in-medium $\pi\pi$ scattering amplitude and pion selfenergy in a hot $\pi N\Delta$ gas. The contributions to the pion selfenergy are…

Nuclear Theory · Physics 2010-11-01 R. Rapp , J. Wambach

We study the bulk viscosity of a pion gas in unitarized Chiral Perturbation Theory at low and moderate temperatures, below any phase transition to a quark-gluon plasma phase. We argue that inelastic processes are irrelevant and…

High Energy Physics - Phenomenology · Physics 2015-05-27 Antonio Dobado , Felipe J. Llanes-Estrada , Juan M. Torres-Rincon

The equation of state for the pion gas is analyzed within the third virial approximation. The second virial coefficient is found from the pion-pion- scattering data, while the third one is considered as a free parameter. The proposed model…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Kostyuk , M. Gorenstein , H. Stoecker , W. Greiner

Within the Matsubara formalism we derive expressions for the pion self-energy and the two-pion propagator in a hot pion gas. These quantities are used to selfconsistently calculate the in-medium $\pi\pi$ amplitude beyond the quasiparticle…

Nuclear Theory · Physics 2016-09-08 R. Rapp , J. Wambach

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature, introducing a chemical potential to describe the finite pion number density. Such description is particularly important during the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alejandro Ayala
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