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arXiv · 2103.04896

Derivation of the nonlocal collision term in the relativistic Boltzmann equation for massive spin-1/2 particles from quantum field theory

Nora Weickgenannt·Enrico Speranza·Xin-li Sheng·Qun Wang·Dirk H. Rischke
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Abstract

We derive the Boltzmann equation and the collision kernel for massive spin-1/2 particles, using the Wigner-function formalism and employing an expansion in powers of $\hbar$. The phase space is enlarged to include a variable related to the spin degrees of freedom. This allows to reduce the transport equations of the independent components of the Wigner function to one scalar equation. To next-to-leading order in $\hbar$, we find that the collision kernel contains both local and nonlocal terms. We show that off-shell contributions cancel in the Boltzmann equation. Our framework can be used to study spin-polarization phenomena induced by vorticity as recently observed in heavy-ion collisions and in condensed-matter systems.

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Nora Weickgenannt, Enrico Speranza, Xin-li Sheng, Qun Wang, Dirk H. Rischke. 2021-03-08. Derivation of the nonlocal collision term in the relativistic Boltzmann equation for massive spin-1/2 particles from quantum field theory. https://doi.org/10.1103/physrevd.104.016022

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