Abstract

Searches for exotic hadrons have taken on a new urgency in recent years with the goal of providing stronger constraints on hadronisation models. Studies of B->DDh decays stand to make a great impact on this exciting field, providing sensitivity to the spectra of conventional charmonium or open-charm resonances, as well as possible exotic states. Such decays have been largely unexplored, for spectroscopy, until now. I will present the first analyses of resonant structure in B+->D+D-K+ decays, using LHCb data, and the discovery of the first open-charm tetraquark candidate, the X(2900). I will discuss the interpretation of this surprising object and its wider context amongst a flood of recent tetraquark- and pentaquark-candidate discoveries.