The Next Chapter for the Dynamical Diquark Model

Almost twenty years of direct study pointed towards the experimentally evidenced heavy-quark exotic hadrons has produced a multitude of appealing theoretical paradigms. Still, no single picture has emerged as the undeniable forerunner. In 2014, a paper published by Brodsky, Hwang, and Lebed introduced a picture that is now the foundation of the Dynamical Diquark Model. This model has since produced a number of exciting results, and continues to survive the seemingly endless onslaught of new experimental data being produced in this field. However, it was not until recently that an attempt was made to incorporate so-called 'threshold effects' into the model. It seems that it must be no coincidence that so many exotic states lie just below (or even just above) the energy threshold of di-hadron configurations. In this presentation, we will review the core components of the dynamical diquark picture and model, and describe how the incorporation of the diabatic formalism (an extension of the adiabatic approximation) may allow for these threshold effects to manifest.