2019-04-17 14:00-15:30  P7F

Quantum kinetic theory for spin transport and anomalous effects/Dr. Di-Lun Yang

Dr. Di-Lun Yang

Recently, the anomalous transport associated with quantum anomalies and spin effects has aroused great interest in relativistic heavy ion collisions (HIC), Weyl semimetals, and lepton transport in astrophysics. In particular, to understand the non-equilibrium anomalous transport, there has been intensive studies upon quantum kinetic theory (QKT) for relativistic fermions incorporating the chiral anomaly. I will review the recent development in QKT for massless fermions known as the chiral kinetic theory (CKT) obtained from the Wigner-function approach based on quantum field theory (QFT) and its applications to relativistic chiral fluids composed of Weyl fermions. Furthermore, motivated by the recent observation of the global polarization of Lambda hyperons, I will introduce a newly developed QKT for massive fermions dubbed as the axial kinetic theory (AKT). Unlike the massless case, where the spin of fermions is enslaved by chirality and momenta, the spin of massive fermions is also a dynamical degree of freedom. The AKT accordingly tracks both the dynamics of vector/axial charges and spin polarization, which consistently reduces to CKT and manifests the spin enslavement by chirality in the massless limit. In the end, I will briefly discuss the potential applications of CKT and AKT in astrophysics and HIC.