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arXiv · 1102.0017

The Bulk Viscosity of a Pion Gas

Egang Lu·Guy D. Moore
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Abstract

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 processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity zeta ~ (F_0^8/m_\pi^5) exp(2m_\pi/T), where F_0 = 93 MeV is the pion decay constant.

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Egang Lu, Guy D. Moore. 2011-01-31. The Bulk Viscosity of a Pion Gas. https://doi.org/10.1103/physrevc.83.044901

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