Analysis of the $Z_c(4200)$ as axial-vector molecule-like state

TL;DR

This paper investigates the $Z_c(4200)$ as an axial-vector molecule-like state using QCD sum rules, finding results consistent with experimental data and supporting its classification as a color octet-octet state.

Contribution

It introduces a novel QCD sum rule analysis of the $Z_c(4200)$ as a color octet-octet axial-vector molecule-like state, providing mass and width predictions.

Findings

Mass and width predictions align with experimental data.

Supports $Z_c(4200)$ as a color octet-octet molecule-like state.

Discusses possible tetraquark assignments for related states.

Abstract

In this article, we assume the $Z_c(4200)$ as the color octet-octet type axial-vector molecule-like state, and construct the color octet-octet type axial-vector current to study its mass and width with the QCD sum rules. The numerical values $M_{Z_c(4200)}=4.19 \pm 0.08\,\rm{GeV}$ and $\Gamma_{Z_c(4200)}\approx 334\,\rm{MeV}$ are consistent with the experimental data $M_{Z_c(4200)} = 4196^{+31}_{-29}{}^{+17}_{-13} \,\rm{MeV}$ and $\Gamma_{Z_c(4200)} = 370^{+70}_{-70}{}^{+70}_{-132}\,\rm{MeV}$, and support assigning the $Z_c(4200)$ to be the color octet-octet type molecule-like state with $J^{PC}=1^{+-}$. Furthermore, we discuss the possible assignments of the $Z_c(3900)$, $Z_c(4200)$ and $Z(4430)$ as the diquark-antidiquark type tetraquark states with $J^{PC}=1^{+-}$.