Mechanism of color confinement in Quantum Chromodynamics

Determine the fundamental mechanism of color confinement within Quantum Chromodynamics that prevents the observation of free quarks and gluons as asymptotic states, and characterize how this mechanism manifests in hadron properties and spectra.

Background

Quantum Chromodynamics is the established theory of strong interactions, describing quarks and gluons as colored degrees of freedom. Despite decades of experimental validation and theoretical progress, the phenomenon of color confinement—the empirical fact that quarks and gluons are never observed in isolation—lacks a definitive, universally accepted theoretical explanation. This gap in understanding is central to hadron physics and underpins many open directions in nonperturbative QCD.

Resolving the confinement mechanism would clarify how observable hadrons emerge from elementary colored constituents and connect to related phenomena such as dynamical chiral symmetry breaking. The Electron-Ion Collider program is motivated, in part, by the need to probe the nonperturbative regime where confinement operates, linking theory to precise measurements of hadron structure.