Speaker
Description
While the charmonium spectrum below the open-charm threshold is well established, the situation above threshold remains murky. Conventional charmonium states become broader and less well explored. At the same time, a wealth of new, potentially exotic hadrons—the XYZ states—challenge the conventional quark-model picture. The BESIII experiment, using e+e− annihilation to produce pairs of charm and anti-charm quarks, is particularly well suited to study the spectrum of those charmonium(-like) hadrons that have the same quantum numbers as the photon: the vector states. In this talk, I will present an overview of the experimental situation around the vector states above the open-charm threshold, and our ongoing efforts towards an interpretation of the data.