Topic: Emergence of near-threshold structures in heavy hadron spectrum

Speaker: Prof. Fengkun Guo

Coordinates: PCFT C1124, 4pm, Thursday, Jul. 8

Abstract: Tremendous progress has been made experimentally in the hadron spectrum containing heavy quarks in the last two decades. It is surprising that many resonant structures are around thresholds of a pair of heavy hadrons. By constructing a nonrelativistic effective field theory with open channels, we show that nontrivial near-threshold structures can show up as only for channels with attractive interaction, and the structure is more poronounced for heavier hadrons. Then, using a vector-meson dominance model for the interaction between two charmed hadrons, we find that there is always a near-threshold pole for attractive charmed hadron pairs. A mass spectrum of more than 200 hadronic molecules are predicted. The observed near-threshold structures with hidden-charm, like the famous X(3872) and Pc states, fit into the spectrum, and many more predicted states are to be explored experimentally.