Possible tetraquark states in the $\pi^+ \chi_{c1}$ invariant mass distribution

TL;DR

This paper investigates the possibility of hidden charmed tetraquark states contributing to the $^+ _1$ invariant mass distribution using QCD sum rules, finding their predicted masses do not match experimental data.

Contribution

It introduces a calculation of vector hidden charmed tetraquark masses with QCD sum rules, proposing alternative interpretations for observed states.

Findings

Predicted tetraquark masses are around 5.12-5.16 GeV.

Predicted masses are inconsistent with experimental data.

Alternative explanations include meson resonances or molecular states.

Abstract

In this article, we assume that there exist hidden charmed tetraquark states with the spin-parity $J^P=1^-$, and calculate their masses with the QCD sum rules. The numerical result indicates that the masses of the vector hidden charmed tetraquark states are about $M_{Z}=(5.12\pm0.15) \rm{GeV}$ or $M_{Z}=(5.16\pm0.16) \rm{GeV}$, which are inconsistent with the experimental data on the $\pi^+ \chi_{c1}$ invariant mass distribution. The hidden charmed mesons $Z_1$, $Z_2$ or $Z$ may be scalar hidden charmed tetraquark states, hadro-charmonium resonances or molecular states.