From Chiral Kinetic Theory To Relativistic Viscous Spin Hydrodynamics

TL;DR

This paper develops a relativistic spin hydrodynamics framework from chiral kinetic theory, incorporating quantum vorticity effects and viscous corrections to predict hadron spin polarization.

Contribution

It introduces a second-order dissipative relativistic fluid dynamics model with spin polarization derived from chiral kinetic theory, including quantum vorticity corrections.

Findings

Derived equations of motion for spin hydrodynamics.

Included quantum vorticity effects in charge currents and stress tensor.

Provided a self-consistent method to predict hadron spin polarization.

Abstract

In this work, we start with chiral kinetic theory and construct the spin hydrodynamic framework for a chiral spinor system. Using the 14-moment expansion formalism, we obtain the equations of motion of second-order dissipative relativistic fluid dynamics with non-trivial spin polarization density. In a chiral spinor system, the spin alignment effect could be treated in the same framework as the Chiral Vortical Effect (CVE). However, the quantum corrections due to fluid vorticity induce not only CVE terms in the vector/axial charge currents but also corrections to the stress tensor. In this framework, viscous corrections to the hadron spin polarization are self-consistently obtained, which will be important for the precise prediction of the polarization rate for the observed hadrons, e.g. $\Lambda$-hyperon.