Hadronic Molecules and $\chi_{cJ}(2P)$ Coupled States

Some hadrons are challenging to describe as conventional hadrons, which are made up of a quark-antiquark pair or three quarks. These are known as exotic hadrons. Since the discovery of $X(3872)$ by the Belle experiment in 2003, additional exotic hadrons containing charm quarks have been reported. Exotic hadrons probably have more intricate structures than ordinary hadrons, although this remains uncertain. For $X(3860)$, $X(3872)$, and $Z(3930)$, which are exotic hadrons of the same quantum number as $\chi_{cJ}(2P)$, we give a unified description of these particles by considering hadronic molecules and bare $\chi_{cJ}(2P)$ coupled states. We consider one-boson exchange including vector-meson exchange as an interaction of hadronic molecules.