Abstract
Over the last decade, experiments at RHIC and at the LHC have
demonstrated that the fragmentation pattern of highly energetic partons
is altered strongly in ultra-relativistic nucleus-nucleus collisions.
This so-called jet quenching motivates using such hard processes as
well-calibrated hard probes of dense QCD matter. A central challenge for
theoretical work is to relate, in a quantitatively controlled and
unambiguous way, the observed jet quenching to fundamental properties of
the QCD matter that induces them.
I will give an introduction to the phenomenology and theoretical
interpretation of jet quenching and discuss the recent attempt to
describe the modification of jets based on perturbative QCD alone.