Researchers have developed a new theoretical framework that describes jet fragmentation in heavy-ion collisions, integrating medium-induced energy loss and color decoherence effects. This advance is crucial for understanding how particle jets, produced in high-energy collisions at accelerators like the LHC, interact with the quark-gluon plasma (QGP) that forms. The model is based on the resummation of large energy logarithms, exploiting the characteristic scale hierarchy of the jet quenching phenomenon.

The study reveals that the jet function obeys the Banfi-Marchesini-Smye evolution equation, where the initial conditions encode energy loss and color decoherence. This structure establishes a direct connection with saturation physics, a regime where gluon density is so high that their nonlinear interactions become dominant. In particular, the coherence angle emerges as an analog of the saturation scale and exhibits the same asymptotic scaling behavior under nonlinear evolution, suggesting a deep relationship between these two phenomena.

As a proof of principle, the authors computed the jet nuclear modification factor, a key observable that quantifies the suppression of jet production in heavy-ion collisions compared to proton-proton collisions. This calculation allows for the evaluation of the interplay between vacuum radiation and medium-induced color decoherence. This new framework provides a unified perturbative description of vacuum-like parton showers, medium-induced radiation, and color-coherence effects, paving the way for precision studies of jet quenching at RHIC and the LHC.