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


Abstract in English

We study the processes $e^+ e^- to Y(4260) to J/psi pipi(Kbar{K})$. The strong final-state interactions, especially the coupled-channel ($pipi$ and $Kbar{K}$) 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.

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