  We propose a new description of the jet quenching phenomenon observed in
nuclear collisions at high energies in which coherent parton branching plays a
central role. This picture is based on the appearance of a dynamically
generated scale, the jet resolution scale, which controls the transverse
resolution power of the medium to simultaneously propagating color probes.
Since from the point of view of the medium all partonic jet fragments within
this transverse distance act coherently as a single emitter, this scale allows
us to rearrange the jet shower into effective emitters. We observe that in the
kinematic regime of the LHC, the corresponding characteristic angle is
comparable to the typical opening angle of high energy jets such that most of
the jet energy is contained within a non-resolvable color coherent inner core.
Thus, a sizable fraction of the jets are unresolved, losing energy as a single
parton without modifications of their intra-jet structure. This new picture
provides a consistent understanding of the present data on reconstructed jet
observables and constitute the basis for future developments.
