Orateur
Kai Zhu
(Institute of High Energy Physics, CAS, China)
Description
In recent years, a number of charmonium-like states have been observed above the open-charm threshold in various experiments. Their properties often go against our expectations for regular charmonium states, rendering their interpretation difficult. With BESIII, we are a leading contributor to the experimental studies of the so-called XYZ states – studying Y-states directly in e+e- annihilation, while producing X and Z states in hadronic and radiative transitions. In this talk, several very recent results from the BESIII program on charmonium-like states above the open-charm threshold will be discussed.
Main references: arXiv:2505.13222; Phys. Rev. Lett. 135, 071901 (2025); Phys. Rev. D 112, 032002 (2025); Phys. Rev. D 111, 112007 (2025)
