# Axialvector tetraquark candidates for the $Z_c(3900)$, $Z_c(4020)$, $Z_c(4430)$, $Z_c(4600)$

## TL;DR

This study systematically investigates axialvector tetraquark states with specific quantum numbers using QCD sum rules, identifying candidates for several observed exotic mesons.

## Contribution

The paper constructs axialvector and tensor currents and applies QCD sum rules to identify tetraquark candidates for known $Z_c$ states, providing new theoretical insights.

## Key findings

- Identifies one axialvector tetraquark candidate for $Z_c(3900)$ and $Z_c(4430)$.
- Finds two candidates for $Z_c(4020)$.
- Finds three candidates for $Z_c(4600)$.

## Abstract

In this paper, we construct the axialvector and tensor current operators to investigate the ground state tetraquark states and the first radially excited tetraquark states with the quantum numbers $J^{PC}=1^{+-}$ via the QCD sum rules systematically, and observe that there are one axialvector tetraquark candidate for the $Z_c(3900)$ and $Z_c(4430)$, two axialvector tetraquark candidates for the $Z_c(4020)$, three axialvector tetraquark candidates for the $Z_c(4600)$.