Quantum kinetic theory of spin polarization of massive quarks in perturbative QCD: Leading log

We present the quantum kinetic equation for the spin polarization of massive quarks in leading-log order of perturbative QCD, which describes time evolution of the spin density matrix in momentum space of a massive quark interacting with a background QCD plasma. We find that the time evolution operator of the spin density matrix or the quantum kinetic collision terms are universally of order ₒ^2log (1/ₒ) in terms of the QCD coupling constant ₒ=g^2/ (4). Our quantum kinetic equation is valid for an arbitrary quark mass mm₃, where m₃ is the Debye mass, and can be used to study relaxation dynamics of spin polarization of massive quarks in the perturbative QCD regime.