Finite angle effects in jet quenching

Abstract

The medium that forms in a heavy-ion collision modifies the properties of jets traversing it. These modifications give substantial information about the nature of the medium and, therefore, they are one of the main focuses of the heavy-ion program at LHC. The influence of the medium into highly energetic partons depends on correlators of Wilson lines, which have been studied in perturbation theory and in several phenomenological models. Here, we focus on the antenna configuration, the study of the evolution of the large energy partons resulting from a collinear splitting inside of the medium. In the eikonal limit, the interaction of each daughter parton with the medium can be parametrized by a light-like Wilson line in a given direction. We consider the case in which the angle between these two directions θ is small but such that Lθ is of the order of the medium resolution scale, where L is the size of the medium. We find that finite angle effects give sub-leading corrections to jet broadening. The physical effect in the antenna configuration is to make the decoherence effect larger when finite angle corrections are taken into account.