# Strong decays of the $Y(4660)$ as a vector tetraquark state in solid quark-hadron duality

## TL;DR

This paper investigates the strong decay properties of the Y(4660) particle, proposing it as a vector tetraquark state and using QCD sum rules to match experimental decay widths, supporting its tetraquark interpretation.

## Contribution

It introduces a specific tetraquark current configuration for Y(4660) and calculates decay widths, providing theoretical support for its tetraquark nature based on solid quark-hadron duality.

## Key findings

- Predicted decay width matches experimental data.
- Hadronic coupling favors the $\psi'_0(980)$ molecule assignment.
- Decay to $J/\\psi \\phi(1020)$ is suppressed, aiding in identifying the state.

## Abstract

In this article, we choose the $[sc]_P[\bar{s}\bar{c}]_A-[sc]_A[\bar{s}\bar{c}]_P$ type tetraquark current to study the hadronic coupling constants in the strong decays $Y(4660)\to J/\psi f_0(980)$, $\eta_c \phi(1020)$, $\chi_{c0}\phi(1020)$, $D_s\bar{D}_s$, $ D_s^* \bar{D}^*_s$, $ D_s \bar{D}^*_s$, $D_s^* \bar{D}_s$, $\psi^\prime \pi^+\pi^-$, $J/\psi\phi(1020)$ with the QCD sum rules based on solid quark-hadron quality. The predicted width $\Gamma(Y(4660) )= 74.2^{+29.2}_{-19.2}\,{\rm{MeV}}$ is in excellent agreement with the experimental data $68\pm 11\pm 1 {\mbox{ MeV}}$ from the Belle collaboration, which supports assigning the $Y(4660)$ to be the $[sc]_P[\bar{s}\bar{c}]_A-[sc]_A[\bar{s}\bar{c}]_P$ type tetraquark state with $J^{PC}=1^{--}$. In calculations, we observe that the hadronic coupling constants $ |G_{Y\psi^\prime f_0}|\gg |G_{Y J/\psi f_0}|$, which is consistent with the observation of the $Y(4660)$ in the $\psi^\prime\pi^+\pi^-$ mass spectrum, and favors the $\psi^{\prime}f_0(980)$ molecule assignment. It is important to search for the process $Y(4660)\to J/\psi \phi(1020)$ to diagnose the nature of the $Y(4660)$, as the decay is greatly suppressed.