The Physics of Jet Quenching in Perturbative QCD

Abstract

Hard processes in collider experiments typically produce QCD jets, which have long served as precision tests of QCD in the vacuum. More recently, heavy-ion programs at RHIC and the LHC have offered a novel perspective on jets, establishing them as unique probes of strongly interacting matter. Experimental observations, including the suppression of high-$p_T$ hadrons and jets, provide compelling evidence for the formation of a new state of matter and its strong coupling to energetic partons. These advances have motivated new theoretical approaches to jet quenching that go beyond standard perturbative techniques, aiming to elucidate the mechanisms of energy dissipation and thermalization of energetic partons in the quark-gluon plasma. This review highlights recent progress, beginning with a unified description of medium-induced radiation across the Landau-Pomeranchuk-Migdal regime and its role in turbulent gluon cascades. We then examine radiative corrections that renormalize the transport coefficient $\hat q$, the mechanism of color decoherence in multi-parton systems, and nonlinear QCD evolution equations for jet energy loss. Finally, we confront this framework with experimental measurements, underscoring the need for precision phenomenology to fully exploit the rich data sets from RHIC and the LHC.