More hidden heavy quarkonium molecules and their discovery decay modes

TL;DR

This paper predicts decay modes and partial widths of heavy quarkonium molecules, providing testable predictions to validate their molecular nature through future experiments.

Contribution

It introduces a flavor symmetry analysis and effective Lagrangian approach to calculate decay widths of heavy quarkonium molecules, which is a novel theoretical prediction.

Findings

Predicted partial widths of order MeV for certain decay channels.

Branching ratios estimated between 10^{-2} and 10^{-1}.

Future experiments can test these predictions to validate the molecular model.

Abstract

To validate the molecular description of the observed $Z_b(10610)/Z_b(10650)$ and $Z_c(3900)/Z_c(4025)$, it is valuable to investigate their counterparts, denoted as $Z_{QV}^{(\prime)}$ in this work, and the corresponding decay modes. In this work, we present an analysis of the $Z_{QV}^{(\prime)}$ using flavor symmetry. We also use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism and calculate the partial widths for the isospin conserved channels $Z_{QV}^{(\prime)} \to \eta_Q V$. The predicted partial widths are of an order of MeV for $Z_{QV} \to \eta_Q V$, which correspond to branching ratios of the order of $10^{-2}\sim 10^{-1}$. For $Z_{QV}^\prime \to \eta_Q V$, the partial widths are a few hundreds of keV and the branching ratios are about $10^{-3}$. Future experimental measurements can test our predictions on the partial widths and thus examine the molecule description of heavy quarkoniumlike exotic states.