QCD Organization of Exotic Hadrons Beyond Conventional Configurations

Determine the organizing principles of Quantum Chromodynamics that govern hadronic matter beyond conventional quark–antiquark mesons and three-quark baryons, including the structure and formation mechanisms of multiquark states such as tetraquarks and pentaquarks.

Background

The paper studies heavy-flavor fragmentation into fully heavy tetraquarks using the TQ4Q1.1 fragmentation-function sets within an NRQCD-based framework and threshold-consistent DGLAP evolution. This provides a controlled setting to connect perturbative short-distance production with nonperturbative hadronization inputs encoded in long-distance matrix elements.

In motivating the work, the authors emphasize that exotic hadrons—such as tetraquarks and pentaquarks—challenge current understanding of confinement and hadronization. They explicitly highlight that how QCD organizes matter beyond conventional quark–antiquark and three-quark configurations remains an open issue, which the presented framework aims to help address by supplying predictive fragmentation inputs and uncertainty quantification.