Tetraquark state candidates: $Y(4140)$, $Y(4274)$ and $X(4350)$

TL;DR

This paper investigates the nature of the $Y(4140)$, $Y(4274)$, and $X(4350)$ particles as tetraquark states using QCD sum rules, providing insights into their quantum numbers and internal structure.

Contribution

The study applies QCD sum rules with vacuum condensates up to dimension-10 to assign quantum numbers to these tetraquark candidates, offering new theoretical insights.

Findings

Y(4140) likely a $2^{++}$ tetraquark state

Y(4274) and X(4350) are disfavored as $0^{++}$ or $2^{++}$ tetraquarks

Results support specific quantum number assignments for these states

Abstract

In this article, we tentatively assign the $Y(4140)$, $Y(4274)$ and $X(4350)$ to be the scalar and tensor $cs\bar{c}\bar{s}$ tetraquark states, respectively, and study them with the QCD sum rules. In the operator product expansion, we take into account the vacuum condensates up to dimension-10. In calculations, we use the formula $\mu=\sqrt{M^2_{X/Y/Z}-(2{\mathbb{M}}_c)^2}$ to determine the energy scales of the QCD spectral densities. The numerical results favor assigning the $Y(4140)$ to be the $J^{PC}=2^{++}$ diquark-antidiquark type tetraquark state, and disfavor assigning the $Y(4274)$ and $X(4350)$ to be the $0^{++}$ or $2^{++}$ tetraquark states.