Abstract

Heavy flavour exotic hadrons, and in particular tetraquarks, continue to elude a theoretical understanding and their consistent explanation is one of the most intriguing questions in hadron spectroscopy. It is clear that their origin lies at the interaction scale of QCD and a complete picture requires calculations including the full breadth of QCD interactions. Such calculations can be provided using lattice QCD . In this presentation the progress and status in studying doubly heavy tetraquark states using this technique is reviewed. After briefly discussing the methodology and some phenomenological considerations I review the status of the available lattice studies in the flavour channel u dbar Qbar Q and also mention in passing further combinations. Our own efforts to study the ground state of these channels are highlighted alongside a study of their heavy quark mass dependence. The presented results suggest the binding energy follows the behaviour argued from phenomenology and confirms its predictions in a regime where the heavy component is above or around charm quark mass. Gathering and comparing recent results from the community where possible a consistent picture for these doubly heavy tetraquarks is emerging.