Color decoherence of in-medium jet evolution

We give a brief overview of recent theoretical studies on the alteration of color coherence in the process of jet fragmentation in the presence of a dense QCD medium. Two regimes emerge depending on the interplay between the typical size of the jet inside the medium r⊥=θjetL, where θjet is the jet opening angle and L the length of medium, and the in-medium transverse color correlation length Qs−1≡(q-hat L)−1/2, where q-hat is the jet quenching parameter. When Qs−1≫r⊥ the medium does not resolve the inner structure of the jet. In this coherence regime the medium will induce radiation off the total charge of the jet while its fragmentation will proceed coherently as in vacuum. In the opposite case Qs−1≪r⊥, the medium resolves more charges inside the jet which will decohere due to rapid color randomization from the jet and fragment independently. A probabilistic picture of in-medium jet fragmentation can be formulated in the total decoherence regime