Decipher the width of the $X(3872)$ via the QCD sum rules

TL;DR

This paper uses QCD sum rules to analyze the decay width of the $X(3872)$, supporting its classification as a hidden-charm tetraquark with a very narrow decay width consistent with experimental data.

Contribution

First to reproduce the tiny decay width of $X(3872)$ via QCD sum rules, confirming its tetraquark nature with $J^{PC}=1^{++}$.

Findings

Decay width approximately 1 MeV

Agreement with experimental decay width

Supports tetraquark interpretation of $X(3872)$

Abstract

In this work, we take the $X(3872)$ as the hidden-charm tetraquark state with both isospin $I=0$ and $1$ components, then investigate the strong decays $X(3872)\to J/\psi \pi^+\pi^-$, $J/\psi\omega$, $\chi_{c1}\pi^0$, $D^{*0}\bar{D}^0$ and $D^{0}\bar{D}^0\pi^0$ with the QCD sum rules. We take account of all the Feynman diagrams, and acquire four QCD sum rules based on rigorous quark-hadron duality. We obtain the total decay width about $1\,\rm{MeV}$, which is in excellent agreement with the experiment data $ \Gamma_{X}=1.19\pm 0.21\,\rm{MeV}$ from the Particle Data Group, it is the first time to reproduce the tiny width of the $X(3872)$ via the QCD sum rules, which supports assigning the $X(3872)$ as the hidden-charm tetraquark state with the $J^{PC}=1^{++}$.