We determine the energy loss spectrum per time-interval of a relativistic
charge traversing a dispersive medium. Polarization and absorption effects in
the medium are modelled via a complex index of refraction. We find that the
spectrum amplitude becomes exponentially damped due to absorption mechanisms.
Taking explicitly the effect of multiple scatterings on the charge trajectory
into account, we confirm results obtained in a previous work.Comment: 4 pages, Proceedings of the 5th International Conference on Hard and
Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2012),
27 May - 1 June 2012, Cagliari, Ital