# Light tetraquark state candidates

## TL;DR

This study uses QCD sum rules to predict masses of $ssar{s}ar{s}$ tetraquark states, supporting the identification of a new state with experimental data and clarifying the nature of related tetraquarks.

## Contribution

It provides the first QCD sum rule predictions for $ssar{s}ar{s}$ tetraquark states, supporting the assignment of a new $X$ state as a $J^{PC}=1^{+-}$ tetraquark.

## Key findings

- Predicted mass of axialvector tetraquark matches experimental data.
- Disfavors $ ext{Y}(2175)$ as a vector partner of the new state.
- Light tetraquarks are around 2 GeV, not 1 GeV.

## Abstract

In this article, we study the axialvector-diquark-axialvector-antidiquark type scalar, axialvector, tensor and vector $ss\bar{s}\bar{s}$ tetraquark states with the QCD sum rules. The predicted mass $m_{X}=2.08\pm0.12\,\rm{GeV}$ for the axialvector tetraquark state is in excellent agreement with the experimental value $(2062.8 \pm 13.1 \pm 4.2) \,\rm{MeV}$ from the BESIII collaboration and supports assigning the new $X$ state to be a $ss\bar{s}\bar{s}$ tetraquark state with $J^{PC}=1^{+-}$. The predicted mass $m_{X}=3.08\pm0.11\,\rm{GeV}$ disfavors assigning the $\phi(2170)$ or $Y(2175)$ to be the vector partner of the new $X$ state. As a byproduct, we obtain the masses of the corresponding $qq\bar{q}\bar{q}$ tetraquark states. The light tetraquark states lie in the region about $2\,\rm{GeV}$ rather than $1\,\rm{GeV}$.