Kinetic theory and hydrodynamics for spin-1/2 particles with nonlocal collisions

by Dr Nora Weickgenannt (Goethe University of Frankfurt, Germany)

Tuesday 29 Sept 2020, 17:00 → 19:00 Asia/Tehran

Online

Webinar on Quark Matter and Relativistic Hydrodynamics

Abstract:

We study the Wigner function for massive spin-1/2 particles up to first order in the Planck constant \hbarℏ. First considering the collisionless limit, we derive a generalized Boltzmann equation in which the force exerted by an inhomogeneous electromagnetic field on the particle dipole moment arises naturally. Furthermore, a kinetic equation for this dipole moment is derived. Carefully taking the massless limit we find agreement with previous results. We then derive the collision term in the Boltzmann equation using the equation of motion for the Wigner function. To next-to-lowest order in \hbarℏ it contains a nonlocal contribution, which is responsible for the conversion of orbital into spin angular momentum. In a proper choice of pseudo-gauge the antisymmetric part of the energy-momentum tensor arises solely from this nonlocal contribution. We show that the collision term vanishes only in global equilibrium and that the spin potential is then equal to the thermal vorticity. In the nonrelativistic limit, the equations of motion for the energy-momentum and spin tensors reduce to the well-known form for hydrodynamics for micropolar fluids.

Join          Webpage