Another tetraquark structure in the $\pi^+ \chi_{c1}$ invariant mass distribution

TL;DR

This paper investigates the possibility that the Z(4250) is a scalar hidden charm tetraquark state using QCD sum rules, providing a mass estimate consistent with experimental data.

Contribution

It introduces a new tetraquark interpretation for the Z(4250) and calculates its mass using QCD sum rules, supporting the tetraquark hypothesis.

Findings

Mass estimate of $4.36 ext{ GeV}$ for the tetraquark state

Z(4250) mass aligns with the tetraquark interpretation

Other interpretations like hadro-charmonium are not ruled out

Abstract

In this article, we assume that there exists a scalar hidden charm tetraquark state in the $\pi^+ \chi_{c1}$ invariant mass distribution, and study its mass using the QCD sum rules. The numerical result $M_{Z}=(4.36\pm0.18) \rm{GeV}$ is consistent with the mass of the Z(4250). The Z(4250) may be a tetraquark state, other possibilities, such as a hadro-charmonium resonance and a $D_1^+\bar{D}^0+ D^+\bar{D}_1^0$ molecular state are not excluded.