Light-quark components analysis and the nature of the $Y(4260)$

Abstract

We study the processes $e^{+}{e}^{-}\to Y(4260)\to J/\psi \pi \pi (K\bar{K})$. The strong final-state interactions, especially the coupled-channel ($\pi \pi$ and $K\bar{K}$) final-state interaction in the $S$-wave are taken into account in a model-independent way using dispersion theory. It is found that the light-quark SU(3) octet state plays a significant role in these transitions, implying that the $Y(4260)$ contains a large light-quark component. Our findings suggest that the $Y(4260)$ is neither a hybrid nor a conventional charmonium state. Furthermore, through an analysis of the ratio of the light-quark SU(3) octet and singlet components, we show that the $Y(4260)$ does not behave like a pure $\bar{D}{D}_1$ hadronic molecule as well.

Comments: 5 pages, proceedings for the 18th International Conference on Hadron Spectroscopy and Structure (Hadron 2019)