Radiative energy loss in an anisotropic Quark-Gluon-Plasma

We calculate radiative energy loss of heavy and light quarks in anisotropic medium (static) in first order opacity expansion. Such an anisotropy can result from the initial rapid longitudinal expansion of the matter, created in relativistic heavy ion collisions. Significant dependency of the energy loss on the anisotropy parameter ($\xi$) and the direction of propagation of the partons with respect to the anisotropy axis is found. It is shown that the introduction of early time momentum-space anisotropy can enhance the fractional energy loss in the direction of the anisotropy, whereas it decreases when the parton propagates perpendicular to the direction of the anisotropy.