Jet quenching in a three-dimensional hydrodynamic medium

We study the radiative energy loss of hard partons in a soft medium in the multiple soft scattering approximation. The soft medium is described by a 3D hydrodynamical model and we treat the averaging over all possible parton paths through the medium without approximation. While the nuclear suppression factor R-AA does not reflect the high quality of the medium description (except in a reduced systematic uncertainty in extracting the quenching power of the medium), the hydrodynamical model also allows to study different centralities and in particular the angular variation of R-AA with respect to the reaction plane, allowing for a controlled variation of the in-medium path-length. We study the angular dependence of R-AA for different centralities, discuss the influence of hydrodynamical expansion and flow and comment on the comparison with preliminary data.