Hadronic molecules in the Heavy Quark Sector
Author: Martin Cleven
The discovery of the exotic state X(3872) at the beginning of this century led to a revival in hadron spectroscopy. In the following years a number of states composed by two quarks and two anti-quarks, commonly referred to as XYZ states, have been found that seem to be at conflict with the interpretation as conventional quark anti-quark mesons. This culminated in the discovery of the Zc(3900) at BES III in 2013. In this talk I will introduce the concept of Hadronic Molecules and show how it might provide an explanation for the nature of some of the XYZ states, in particular I will focus on the charmonia Y(4260) and Zc(3900).