  We investigate the energy loss and equilibration of highly energetic
particles/jets inside a QCD medium. Based on an effective kinetic description
of QCD, including $2\leftrightarrow 2$ elastic processes, radiative
$1\leftrightarrow 2$ processes, as well as the back-reaction of jet
constituents onto the thermal medium, we describe the in-medium evolution of
jets from the energy scale of the jet $\sim E$ all the way to the medium scale
$\sim T $. While elastic processes and back-reaction are important to describe
the equilibration of soft fragments of the jet, we find that the energy loss is
dominated by an inverse turbulent cascade due to successive radiative
branchings, which has interesting implications for the energy spectra and
chemistry of jet fragments.
