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arXiv · 2402.06996

Transport coefficients of transient hydrodynamics for the hadron-resonance gas and thermal-mass quasiparticle models

Gabriel S. Rocha·Gabriel S. Denicol
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Abstract

We calculate all transport coefficients of second order transient hydrodynamics in two effective kinetic theory models: a hadron-resonance gas and a quasiparticle model with thermal masses tuned to reproduce QCD thermodynamics. We compare the corresponding results with calculations for an ultrarelativistic single-component gas, that are widely employed in hydrodynamic simulations of heavy ion collisions. We find that both of these effective models display a qualitatively different normalized bulk viscosity, when compared to the calculation for the single-component gas. Indeed, $\zeta/[\tau_{\Pi}(\varepsilon_{0} + P_{0})] \simeq 16.91(1/3-c_{s}^{2})^{2}$, for the hadron-resonance gas model, and $\zeta/[\tau_{\Pi}(\varepsilon_{0} + P_{0})] \simeq 5 (1/3-c_{s}^{2})$ for the quasiparticle model. Differences are also observed for many second-order transport coefficients, specially those related to the bulk viscous pressure. The transport coefficients derived are shown to be consistent with fundamental linear stability and causality conditions.

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Gabriel S. Rocha, Gabriel S. Denicol. 2024-02-10. Transport coefficients of transient hydrodynamics for the hadron-resonance gas and thermal-mass quasiparticle models. https://doi.org/10.1103/physrevd.109.096011

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