Hard loop approach to anisotropic systems

Anisotropic systems of quarks and gluons, which at least for sufficiently short space-time intervals can be treated as homogeneous and static, are considered. The gluon polarization tensor of such a system is explicitly computed within the semiclassical kinetic and hard loop diagrammatic theories. The equivalence of the two approaches is demonstrated. The quark self-energy is computed as well, and finally, the dispersion relations of quarks and gluons in the anisotropic medium are discussed.