  For jets, with great power comes great opportunity. The unprecedented center
of mass energies available at the LHC open new windows on the QGP: we
demonstrate that jet shape and jet cross section measurements become feasible
as a new, differential and accurate test of the underlying QCD theory. We
present a first step in understanding these shapes and cross sections in heavy
ion reactions. Our approach allows for detailed simulations of the experimental
acceptance/cuts that help isolate jets in such high-multiplicity environment.
It is demonstrated for the first time that the pattern of stimulated gluon
emission can be correlated with a variable quenching of the jet rates and
provide an approximately model-independent approach to determining the
characteristics of the medium-induced bremsstrahlung spectrum. Surprisingly, in
realistic simulations of parton propagation through the QGP we find a minimal
increase in the mean jet radius even for large jet attenuation. Jet broadening
is manifest in the tails of the energy distribution away from the jet axis and
its quantification requires high statistics measurements that will be possible
at the LHC.
