Speaker
Description
Exotic hadrons have attracted lots of interests in recent years and there are many experimental candidates of such states. We focus on the bound state of $D^* \bar D_1$ with the exotic quantum numbers $J^{PC}=0^{--}$, named as $\psi_0 (4360)$. We predict the existence of the $\psi_0 (4360)$ and its binding energy with parameters determined by assuming the $\psi(4230)$,$\psi(4360)$ and $\psi(4415)$ states be the $D \bar D_1$, $D^* \bar D_1$ and $D^* \bar D_2$ molecules, respectively. We mainly focus on the $t$ channel vector- and pseudoscalar-meson exchange, including couped-channel effects. We also discuss the $u$ channel pion exchange, which contributes to the long range interaction. In this case the pion can go on-shell, the $D^* \bar D^* \pi$ three body effects have been properly treated. It turns out that the $t$ channel potential is enough to form a bound state, $\psi_0 (4360)$, and the $u$ channel effect does not change the qualitative conclusion. Since the $\psi(4360)$ is located in the same mass range, we discuss how to distinguish these two particles by an anglar distribution analysis.
