Fermi-liquid view of viscosity in cold and dense nucleon matter

Abstract:

We develop a framework to calculate transport properties in cold, dense relativistic quasiparticle system within the Fermi-liquid theory at the mean-field level. Building on our previous study J. Li et al. [Phys. Rev. C 111, 044904 (2025)], we start from the linearized relativistic Boltzmann equation tailored to quasiparticles with medium-dependent dispersion relation and implement Landau matching conditions, proving that the bulk viscosity is manifestly nonnegative. A low-temperature expansion then yields leading-order (𝑇/𝜇*) expressions for the shear (𝜂) and bulk (𝜁) viscosities, where the behavior 𝜁/𝜂∝(𝑇/𝜇*)4 in the degenerate regime is found to be robust against quasiparticle mass correction. We couple the kinetic framework to a Walecka-type mean-field equation of state and compute 𝜂 and 𝜁 for cold, dense nucleon matter. The transport properties of nucleonic matter in the degenerate regime can be relevant for intermediate beam-energy nuclear experiments.

J. Li, W. Ke, J. Hu, „Fermi-liquid view of viscosity in cold and dense nucleon matter“, Phys. Rev. C 113, 064901 (2026).

https://journals.aps.org/prc/abstract/10.1103/77kj-8v36

Related to Project C06