TY  - JOUR
AU  - Wagner, David
AU  - Shokri, Masoud
AU  - Rischke, Dirk H.
TI  - Damping of spin waves
JO  - Physical review research
VL  - 6
IS  - 4
SN  - 2643-1564
CY  - College Park, MD
PB  - APS
M1  - GSI-2025-00284
SP  - 043103
PY  - 2024
N1  - Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license.
AB  - We show that, in ideal-spin hydrodynamics, the components of the spin tensor follow damped wave equations. The damping rate is related to nonlocal collisions of the particles in the fluid, which enter at first order in in a semiclassical expansion. This rate provides an estimate for the timescale of spin equilibration and is computed by considering a system of spin-1/2 fermions interacting via a quartic self-interaction as well as via (screened) one-gluon exchange. It is found that the relaxation times of the components of the spin tensor can become very large compared to the usual dissipative timescales of the system. Our results suggest that the spin degrees of freedom in a heavy-ion collision may not be in equilibrium by the time of freeze-out, and thus should be treated dynamically.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1103/physrevresearch.6.043103
UR  - https://repository.gsi.de/record/356904
ER  -