The concept of the Wigner function is used to construct a semi-classical kinetic theory describing evolution axial-current phase-space density spin-1/2 particles in relaxation time approximation. resulting approach can be study spin-polarization effects relativistic matter, particular, heavy-ion collisions. An expression for axial current based on classical treatment spin also introduced and we...

A Boltzmann equation for semiconductors is considered. Physical assumptions include the parabolic band approximation and a new relaxation time model for electron-phonon interaction. Thermal equilibrium distributions for this scattering mechanism are products of Maxwellian distributions with periodic functions of the energy, where the period is the energy of a phonon. The hydrodynamic limit is c...