The Exotic XYZ Charmonium-like Mesons

Understand

Charmonium, the spectroscopy of c\bar{c} mesons, has recently enjoyed a renaissance with the discovery of several missing states and a number of unexpected charmonium-like resonances.

• The discovery of these new states has been made possible by the extremely large data samples made available by the B-factories at the Stanford Linear Accelerator Center and at KEK in Japan, and at the CESR e^+e^- collider at Cornell.
• Conventional c\bar{c} states are well described by quark potential models.
• However, many of these newly discovered charmonium-like mesons do not seem to fit into the conventional c\bar{c} spectrum.