Quantitative Theory of Jet Quenching

Develop a quantitative theoretical description of jet quenching—the reduction of jet energies and modification of jet substructure caused by interactions of high-transverse-momentum parton showers with the quark–gluon plasma in heavy-ion collisions—consistent with and constrained by detailed experimental measurements.

Background

Heavy-ion collisions at the LHC and RHIC create a quark–gluon plasma that interacts with high-pT parton showers, leading to observable modifications of jets collectively referred to as jet quenching. While many measurements quantify jet suppression and substructure changes, a comprehensive, predictive theoretical framework that quantitatively describes these phenomena across observables and conditions is not yet established.

The study presented uses ATLAS Pb+Pb and pp data to measure the dependence of jet suppression (R_AA) on large-R jet substructure variables constructed from charged-particle tracks. Such measurements provide detailed experimental input intended to help constrain and guide the development of a quantitative theory of jet quenching.

References

Developing a quantitative theoretical description of jet quenching is an open problem that requires detailed experimental input.

Despite these advances, a fundamental challenge remains unresolved: the construction of a systematic all-order theory of jet quenching.

Color Coherence and the Soft Structure of QCD Jets in Vacuum and the QGP  (2608.25984 - Caucal et al., 26 Aug 2026) in Section 1, Introduction