Theory of hadronic molecules applied to the XYZ states

TL;DR

This paper demonstrates that many heavy quarkonium-like states, previously thought inconsistent with simple quark models, are likely hadronic molecules, and discusses observables sensitive to their molecular nature.

Contribution

It applies the theory of hadronic molecules to interpret XYZ states, providing a framework to understand their molecular nature and identifying sensitive observables.

Findings

Most XYZ states are consistent with a molecular interpretation.

Certain observables are identified as sensitive to the molecular component.

The molecular model explains experimental data better than simple quark models.

Abstract

In recent years data have been accumulated at various experiments about states in the heavy quarkonium mass range that seem to be inconsistent with the most simple variants of the quark model. In this contribution it is demonstrated that most of those data are consistent with a dominant molecular nature of those states. It is also discussed which kind of observables are sensitive to the molecular component and which are not.