  In this work we study the contribution to leptogenesis from Delta L=1 decay
and scattering processes mediated by the Higgs with quarks in the initial and
final states using the formalism of non-equilibrium quantum field theory.
Starting from fundamental equations for correlators of the quantum fields we
derive quantum-corrected Boltzmann and rate equations for the total lepton
asymmetry improved in that they include quantum-statistical effects and medium
corrections to the quasiparticle properties. To compute the collision term we
take into account one- and two-loop contributions to the lepton self-energy and
use the extended quasiparticle approximation for the Higgs two-point function.
The resulting CP-violating and washout reaction densities are numerically
compared to the conventional ones.
