The $Y(4260)$ and $Y(4360)$ enhancements within coupled-channels

Abstract

Puzzling structures have been observed in the charmonium energy region, namely the $Y(4260)$ and the $Y(4360)$, that cannot be easily accommodated within quark model frameworks. The proximity of nearby dominant hadronic thresholds suggests that they play an important role in the formation of the enhancements. We present results of an unitarized effective Lagrangian model, where mesonic loops, equivalent to coupled-channels, and charmonium vectors $\psi$ interplay to generate line-shapes and poles.