Nature of the $Y(4260)$: A light-quark perspective

Abstract

The $Y(4260)$ has been one of the most puzzling pieces among the so-called $XYZ$ states. In this paper, we try to gain insights into the structure of the $Y(4260)$ from the light-quark perspective. We study the dipion invariant mass spectrum of the $e^{+}{e}^{-}\to Y(4260)\to J/\psi {\pi }^{+}{\pi }^{-}$ process and the ratio of the cross sections $\sigma (e^{+}{e}^{-}\to J/\psi K^{+}{K}^{-})/\sigma (e^{+}{e}^{-}\to J/\psi {\pi }^{+}{\pi }^{-})$. In particular, we consider the effects of different light-quark SU(3) eigenstates inside the $Y(4260)$. The strong pion-pion final-state interactions as well as the $K\bar{K}$ coupled channel in the $S$-wave are taken into account in a model-independent way using dispersion theory. We find that the 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, and they are consistent with the $Y(4260)$ having a sizeable $\bar{D}{D}_1$ component which, however, is not completely dominant.

22 pages, 5 figures

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Cited by in corpus (7)

• Pentaquark and Tetraquark states
• Precise determination of the pole position of the exotic $Z_c(3900)$
• Study of the $Y(4660)$ from a light-quark perspective
• Three-body strong decays of the $Y(4230)$ via the light-cone QCD sum rules
• $\varphi (2170)$ decaying to $\varphi \pi \pi$ and $\varphi K\bar{K}$
• Pinpointing Physical Solutions in Y(4230) Decays
• Unified study of $B_s^0\to X(3872){\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ and $B_s^0\to \psi (2S){\pi }^{+}{\pi }^{-}(K^{+}{K}^{-})$ processes